Although PLA is one of the most commonly used materials in 3D printing and one of the most popular bioplastics, not many people know that there is more than one type of PLA out there.

Variations of PLA are mostly based on the ways in which its chemical structure can be altered. The differences may be subtle, but they are significant enough for a few industries and are certainly worth discussing.


Lactic acid as a chiral molecule

Before jumping into the different types of polymer chains that exist for PLA, we need to look at the molecular structure of its constituent monomer – lactic acid. Lactic acid is produced by fermentation of carbohydrate compounds which are typically derived from plant-based material, giving PLA its unique character as a more “sustainable” plastic.

The chemical composition of lactic acid does not change – each unit of lactic acid contains exactly three molecules of carbon, three molecules of oxygen, and six molecules of hydrogen which are connected in a manner that creates specific functional groups. However, there can be variations in how these molecules are oriented in three-dimensional space.

Lactic acid is what is known as a chiral molecule. This means its molecular structure has two mirror images that are distinct from each other. These mirror images are called enantiomers or optical isomers.

To distinguish between these optical isomers, they are commonly referred to as either the L (laevorotatory) or the D (dextrorotatory) isomers based on the direction at which they polarize light.

In the case of lactic acid, its optical isomers are called L-lactic acid and D-lactic acid. A mixture of the optical isomers can also be concocted, which is referred to as a racemic mixture of simply DL-lactic acid.

The process by which lactic acid is created, including the bacteria used for fermentation, can have pronounced effects on which type of isomer lactic acid isomer is produced. Controlling these factors is important because these isomers can have distinct characteristics – for instance, both L-lactic acid and D-lactic acid have a freezing point that’s higher than DL-lactic acid.

Lactic acid as a chiral molecule

Before jumping into the different types of polymer chains that exist for PLA, we need to look at the molecular structure of its constituent monomer – lactic acid. Lactic acid is produced by fermentation of carbohydrate compounds which are typically derived from plant-based material, giving PLA its unique character as a more “sustainable” plastic.

The chemical composition of lactic acid does not change – each unit of lactic acid contains exactly three molecules of carbon, three molecules of oxygen, and six molecules of hydrogen which are connected in a manner that creates specific functional groups. However, there can be variations in how these molecules are oriented in three-dimensional space.

Lactic acid is what is known as a chiral molecule. This means its molecular structure has two mirror images that are distinct from each other. These mirror images are called enantiomers or optical isomers.

To distinguish between these optical isomers, they are commonly referred to as either the L (laevorotatory) or the D (dextrorotatory) isomers based on the direction at which they polarize light.

In the case of lactic acid, its optical isomers are called L-lactic acid and D-lactic acid. A mixture of the optical isomers can also be concocted, which is referred to as a racemic mixture of simply DL-lactic acid.

The process by which lactic acid is created, including the bacteria used for fermentation, can have pronounced effects on which type of isomer lactic acid isomer is produced. Controlling these factors is important because these isomers can have distinct characteristics – for instance, both L-lactic acid and D-lactic acid have a freezing point that’s higher than DL-lactic acid.


As we’ve mentioned, different isomers of lactic acid can have different chemical and physical properties. These differences also translate to their corresponding polymer products. Considering the concept of chirality, we now know there are also three possible PLA polymer chains:


Both PLLA and PDLA can be manufactured by having pure mixtures of either L-lactic acid or D-lactic acid undergo a condensation reaction to produce long polymer chains. Both PLLA and PDLA polymers are naturally crystalline, which means that they take on ordered molecular structures.

PDLLA is created by polymerizing a mixture of both L-lactic acid and D-lactic acid. A 1:1 ratio of both isomers is typically used, the degree of crystallinity of the final polymer can be altered by tweaking with this ratio. In general, however, PDLLA is less crystalline and more amorphous than its PLLA and PDLA counterparts.


The crystalline nature of both PLLA and PDLA gives them almost similar characteristics. They have melting temperatures somewhere within the 170 °C to 180 °C range and are selectively soluble. Crystalline PLLA does not dissolve in many common solvents like acetone, ethyl acetate, and tetrahydrofuran (THF).

On the other hand, PDLA does not decompose when exposed to certain enzymes that can hydrolyze both PLLA and PDLLA.


PDLLA is produced by the copolymerization of L-lactic acid and D-lactic acid or their lactide counterparts. When combined in a 1:1 ratio, the resulting PDLLA becomes an amorphous material with a glass transition temperature of 50 to 60 °C.

The lack of a crystalline structure makes PDLLA more chemically reactive and more prone to biodegradation. Many solvents that do not react with the pure stereoisomers PLLA and PDLA can partially dissolve PDLLA.

As with the pure stereoisomers, molecular weight plays a vital role in determining the physical and chemical characteristics of PDLLA. The 50 to 60 °C glass transition temperature applies for polymer chains with molecular weight of up to 30,000. Keeping the polymer chains short also results in gradual decrease of this glass transition temperature. As with other polymers, this also has effects on physical properties such as tensile strength and flexibility.

Take note that these physical and chemical characteristics can still vary greatly depending on manufacturing methods. Factors such as the rate of crystallization, the molecular weight of the polymer chains, and the ratio of individual components play a significant role in determining the properties of the final polymer. Thus, these differences between PLLA, PDLA, and PDLLA are not absolute.


Even without differentiating between the different types of PLA polymers, we already know some of its more common applications. PLA is a non-toxic plastic that is considered safe for food contact.

The fact that it breaks down into non-toxic lactic acid makes it biocompatible and suitable for sutures and implants that are meant to be absorbed by the human body.

High-molecular weight PLLA is the material of choice for stents and implants that need to maintain their mechanical properties over an extended period. PLLA takes several months to degrade, and this degradation time can be further extended by producing PLLA with higher molecular weight polymer chains.

They have been used for implants meant to facilitate the reconstruction of tendons and ligaments, as well as embolic materials for arterial embolization. PLLA has better chemical stability, better withstands enzyme degradation, and has a much longer resorption time.

PDLLA, on the other hand, breaks down inside the body relatively quickly. While this makes it unsuitable for long-term implants, PDLLA is actually one of the most well-researched bioplastics today.

Its resorption behavior has been studied to a point where scientists can predict when it will degrade under normal physiological conditions. This unique characteristic has made PDLLA an ideal material for many drug-release mechanisms.


Most of us who are into 3D printing have probably spent a lot of time working with PLA without really knowing how complex its chemistry could be. While we may not need to know the difference between PLLA, PDLA, and PDLLA, a little extra knowledge doesn’t hurt.

If you ever find yourself in a situation where you need to 3D print medical implants or devices, it would be nice to know specifically which flavor of PLA you should use.

Things You Should Know About PLLA Injection

Things You Should Know About PLLA Injection

Things You Should Know About PLLA Injection

The world of cosmetics has seen a lot of development and improvement in the past couple of years. From the usual powder and makeup that people wear – to surgeries and implants for a lot of parts of the face and the body.

Among the many different types of aesthetic materials and innovations, PLLA injection has been the most famous and the most used.

In this article, we’ll be discussing about the details about PLLA Injection. Without further ado, let’s head straight on what you should be aware of when it comes to dermal fillers!

Why Use PLLA

PLLA, short for Poly-L-Lactic Acid, is a type of injection that people use for maximal correction and improvement. More common than not, it’s used in correcting facial defects, and it offers a permanent and a long-term solution for patients that have deficits with their facial features.

While there are a lot of other medical grade polymers that are synthetic, a lot of people choose PLA injection because of the following:


One of the main benefits that you can get if you use PLLA is that it’s renewable. In addition to that, it’s also made from raw materials.

Therefore, it’s clear that these are materials that are safe-to-use and that are environmentally friendly.

Excellent Quality Performance

Another advantage that you can get from using it would be with collagen synthesis, which offers deep-tissue regeneration. Because of how they’re structured, they promote the regeneration of cells at a deeper and more serious part.

Its outstanding effects will gradually become more apparent and will increase for over a long period of time, making it a permanent solution to a cosmetic problem that you are experiencing.

PLLA helps in the stimulation of collagen fiber proliferation, therefore, it further strengthens the integrity of the skin.

This is among the many reasons why it’s mostly used for revitalizing the skin in different areas such as the temples, cheeks, the chin, and so on. It’s been deemed as one of the best and the most effective skin preservation materials and ingredients.

Little-to-No Immunogenic Response

You can expect that there’ll be little-to-no negative or immunogenic reactions. But, it’s worth noting that the raw ingredients and/or materials used are safe and are compatible with the wide majority of skin types.

Those are just three (3) of the reasons why you should consider PLLA injections instead of other options. But, there are others; in fact, there are a lot more you can choose from! But with these benefits, you’ll surely not mind the other choices you have.

Microspheres Diameter

When it comes to the content of dermal fillers, they’re packed and filled with content that contribute to the powerful effects of the dermal fillers.

Following that, the microspheres diameter of the content of dermal fillers are distributed evenly. What this means is that it contains solutions that point directly towards its effects – to get rid of wrinkles, lines, and the like.

Injection Position

PLLA is known for its revitalizing nature. That being said, it can straightly be injected in a lot of different positions and places.

However, the most common places would be in the following parts:

  • Lower part of the face
  • Mid-cheek to lower cheek region
  • Temples

To be able to achieve the best results, the needle must be inserted at an angle of 30 to 45 degrees. It needs to be following the flow or the direction of the wrinkle or the inconsistency within the region you’re looking to fix.


In choosing the specific type of PLLA injection or dermal filler you need to utilize, you can find it in many different specifications.

These differences are used to specify the particular use they have for it. PLLA that have higher molecular weights tend to have better physical properties. For instance, those that are heavier can produce and provide more effects than those that are lighter.

Since then, and until today, PLLA that has higher and heavier molecular weight are lactide polymerization through its outer layer.

On the other hand, lower molecular-weighted polymers have increased rates of degradation because of the low intake of water. Furthermore, they have higher concentration of end groups of carboxyl.  

Side Effects

Injectable PLLA is one of the best, but it doesn’t mean it yields no side effects. Akin to how other products and materials are, the usage of PLLA isn’t actually perfect.

As a matter of fact, there could be side effects that might not be comfortable or convenient for you. 

Swelling and Inflammation

Since it‘s applied through deep injection, it can cause inflammatory or swelling reactions that are connected to injections.

These side effects could include:

  • Redness of the area where it was injected
  • Dull and sharp pain within the region of injection  
  • Swelling
  • Itchiness on the area and the surrounding area
  • Temporary lumps

Can Bruising Be a Side Effect?

There have been some cases where people have reported to have seen swelling on the site of injection. It was a mere 21% of the total data and was a pretty high amount.

While these may seem alarming, you can actually take care of these easily. With proper hygiene and care especially on the injection site, you’ll be able to get rid of these.

In addition to those common side effects, there are uncommon side effects that some patients may experience, too. These include:

  • Mild to serious infections
  • Cysts and blisters
  • Scars and marks
  • Numbness

If you’re experiencing any of these on a constant basis, the next best thing to do is to contact the cosmetologist you worked with the PLLA injection you had.

PLGA Polymer: Ultimate Buying Guide

PLGA Polymer: Ultimate Buying Guide

PLGA Polymer: Ultimate Buying Guide

Do you know PLGA(Poly(lactic-co-glycolic acid) are widely used in medical devices?  Yes, there are many types of plga polymer in the market. They have different ratios, viscosity, end group,s, and shapes.

In this PLGA buying guide, I am going to explain the advantages, structure, cost, application, synthesis, and FAQ about this polymer.

What is PLGA Polymer?

It is an Abbreviation, the full name is Poly(lactic-co-glycolic acid). It is polymerized from lactic acid and glycolic acid monomers, By changing the polymer monomer ratio and molecular weight, the degradation rate of the copolymer in the body, DNA encapsulation rate, and gene release rate can be adjusted.

This is the appearance we can see.

PLGA polymer
Maybe you will know PLA material, it is a type of degradable plastic and mainly used in 3d printing and package. Actually PLGA is based on PLA. PLGA Polymerized from lactide and glycolide, Lactide is the monomer of PLA.

Now you will know what is the plga polymer, let me know tell why do you need this material.

PLGA Structure

PLGA is light yellow or colorless substance, Because lactide has three different structures, PLGA also has three structures, PLLGA,PDLGA and PDLLGA. PLLGA and PDLGA are is semi-crystalline, PDLLGA is amorphous.

How to synthesis PLGA?

PLGA is mostly manufactured by ring-opening polymerization. It is the dehydration and cyclization of glycolic acid and lactic acid to synthesize two monomers of glycolide and lactide, and then ring-opening polymerization to obtain PLGA random copolymer.

Another route is to make two polymer monomers of lactic acid and glycolic acid into six-membered cyclic lactide-glycolide, and then ring-opening polymerization to obtain an alternating copolymer of PLGA. The polymer has regular structure, fixed composition and stable degradation performance.

PLGA route

The reaction formula of ring-opening polymerization to synthesize PLGA

Benefits of PLGA polymer(here’s why you need it)

As the types of biomedical polymer materials, PLGA combines the advantages of two materials: polylactic acid and polyglycolic acid. It has good biocompatibility and degradability, which is widely used in the field of biomedicine.

  1. Controllable degradation rate

As we have said, PLGA has different structure, viscosity and ratio(LA: GA).By modifying the component ratio of LA and GA and molecular weight, it can effectively adjust the degradation rate of the copolymer. It is used in Controllable drug/protein delivery systems, tissue engineering scaffolds and other fields.

  1. Easy to Manufacture

PLGA can be processed in many ways, such as extrude, spinning and biaxial stretching. Meanwhile, PLGA can exist in various forms such as microspheres, microcapsules, nanospheres and nanofibers.

  1. cell adsorption and proliferation

PLGA also has the effect of promoting cell adsorption and proliferation.This property makes it a potential tissue engineering application. Many studies have prepared micro-nano-scale PLGA three-dimensional scaffolds.

Limited of PLGA Polymer

The main disadvantage of PLGA polymer is the solubility. PLGA is formed by random copolymerization of lactide and glycolide. If the GA content is too high during the copolymerization process, it will easily form a peg segment with local GA interlinking too long, thereby partially showing the performance of PGA. It makes PLGA difficult to dissolve.

If the GA content in the plga ratio exceeds 50%, the general solvent cannot dissolve it, and the molecular weight cannot be too high in the 50:50 ratio. Generally, the molecular weight is less than 100,000 to ensure methylene chloride It can be dissolved in chloroform, and the molecular weight of 1 million in the ratio of 75:25 can also be dissolved in dichloromethane and chloroform

PLGA mechanical properties

The initial strength of polylactic acid and its copolymers is poor, it is far from meeting the strength requirements of bone materials. PLGA composite prepared by self-reinforcement technology, this can significantly improve mechanical properties.

Self-reinforced PLGA(PGA/PLLA) has high strength and moderate degradation rate, it meets the requirements for internal fixation materials for composite fractures.

LA:GACrystallinityElongationShear modulusTensile strength
100:0High1.5%130-150 Mpa2.10 Mpa
75:25Medium2.7%105-110 Mpa1.36 Mpa
50:50No2.5%85-91 Mpa1.04 Mpa
25:75Medium2.5%79-85 Mpa1.02 Mpa
0:100High2.8%65-72 Mpa1.02 Mpa

PLGA Degradation Process

The biodegradation of polymers is a very complicated process. Degradation time mainly depends on the size and structure of polymer molecules. Types of microorganisms, temperature, enzymes, and other factors.

From a chemical point of view, there are three types of polymer degradation:

  1. Hydrophobic polymers become a low relative molecular weight, water-soluble molecules through the hydrolysis of unstable bonds on the main chain
  2. Water-insoluble polymer becomes water-soluble polymer through hydrolysis, ionization, or protonation of side-chain groups
  3. The water-insoluble polymer is hydrolyzed and the unstable cross-linked chain becomes a water-soluble linear polymer

The degradation of PLGA is mainly carried out by the hydrolysis of ester bonds. The hydrolytic cleavage of the ester bond on the molecular chain is irregular. Each ester bond may be hydrolyzed, The longer the molecular chain, the more parts will be hydrolyzed.

In biological media, first, small molecules of water move to the surface of the polymer material and diffuse into the surrounding ester bonds or hydrophilic groups. Under the action of acid-base or enzyme in the medium, the ester bond is broken by acid-base hydrolysis or degraded by enzymatic hydrolysis.

Application of PLGA

PLGA is currently restricted by its price and other factors, it mainly used in engineering fields such as biomedicine

1. Drug release control system

Release control is to contact the drug or other biologically active substances with the substrate so that the drug can be released into the environment at a certain rate within a certain period of time through diffusion and other means.

Controllable drug release with biodegradable materials as a carrier can gradually release drugs through slow degradation in the body to exert the best effect in the body. PLGA is widely used in drug microspheres due to its good processing and drug release properties

2. Tissue engineering and bone fixation materials

PLGA is non-toxic in the body and has good biocompatibility, it also can participate in the carbohydrate metabolism cycle in the human body without residue. Therefore, his application in tissue engineering is extremely wide.

It can be used as a cell growth carrier in bone tissue regeneration, cartilage tissue regeneration, artificial skin, peripheral nerve repair, etc.

medical suture

3. Medical suture

PLGA can be used as a surgical suture. Due to its biodegradability, it will automatically degrade and absorb after the wound has healed, without the need for a second operation.

This also requires the polymer to have a strong initial tensile strength and be stable for a period of time, while being able to effectively control the degradation rate of the polymer. As the wound heals, the suture slowly degrades.

Top 5 Biodegradable Polymers for Drug Delivery

Top 5 Biodegradable Polymers for Drug Delivery

Top 5 Biodegradable Polymers for Drug Delivery

Biodegradable polymers are often used in drug delivery applications because of their biocompatibility. They can be used as binders in tablets and they work as flow controlling agents in liquids, suspensions, and emulsions.

In addition, they can be used for controlled release and targeting drug delivery systems. They have many useful applications in the field of drug delivery.

What Is Drug Delivery Technology?

Drugs are used to improve people’s health and extend their lives. Drug delivery is the method of getting the drug into a person’s body to help him or her fight an illness. Biomedical engineers have helped scientists understand the physiological barriers in the way of drug delivery, such as how drugs move through cells and tissues, the circulatory system, and more.

The key is to find the best possible way to deliver the drug with the fewest side effects. It is ideal to avoid having the drug interact with healthy tissues and to target those that are unhealthy. Drug delivery technology includes agents designed to control the release of a drug or to target specific organs, cells, tissues, and more.

Drug Delivery Methods

How well a drug can do its job is impacted by how it is delivered. Drugs can be introduced to the body in a number of different ways through different drug delivery methods. These methods include the following:

  • Buccal drug delivery: through the lining of the cheek
  • Nasal drug delivery: through the nasal cavity
  • Ocular drug delivery: through the eye
  • Oral drug delivery: through the mouth
  • Pulmonary drug delivery: inhaled through the mouth into the airways
  • Sublingual drug delivery: absorbed under the tongue into the bloodstream
  • Transdermal drug delivery: application to intact skin
  • Vaginal/anal drug delivery: through the vagina or anus
  • Targeted drug delivery: concentrated delivery of drug to its target

Biodegradable polymers help with targeted drug delivery as well as controlled drug release.

Drug Delivery Impact Factors

There are barriers that need to be researched so that drugs can be more effective in their delivery to specific targets. For example, scientists are studying the blood-brain barrier in brain diseases and disorders. They want to deliver drugs to the brain and prevent harmful substances from entering the brain.

They are also looking at intracellular delivery so that cells that protect the body from a drug will no longer inhibit its ability to reach a target. Scientists are constantly researching new methods to improve delivery of drugs.

What Are the Benefits of Using These Materials

There are many benefits to using biodegradable polymers. They are eco-friendly and have reduced carbon emissions. They also require less fossil fuel consumption for their production, which helps to reduce pollution. They are also made with recyclable material.

Biodegradable materials can be used in drug delivery and the benefit is that they break down over time. They can offer temporary support. In addition, there is no need for future surgical removal. They can be made into different shapes with different rates of degradation.

Biodegradable polymers can assist in drug delivery systems in ways that were not possible before. These systems are able to overcome the limitations offered by traditional drug delivery methods to target specific parts of the body. The solution is more effective and allows local delivery and less frequent doses.

Favorable Materials Used in Drug Delivery

Different biodegradable polymers have proven to be effective as part of a drug delivery system. When they have a hydrophobic nature, they are effectively able to carry and deliver drugs to targeted areas or through controlled release. Take a look at these materials that are favored for use in drug delivery:


PLLA is poly l-lactide acid and it is a biodegradable polymer that can be used in drug delivery. It is biocompatible and biodegradable by hydrolysis and enzymatic activity. It is also FDA-approved and known to be a viable solution for drug delivery. It can carry nanoparticles such as liposomes, polymeric nanoparticles, dendrimers, and micelles. It can also encapsulate toxic anti-tumor drugs and stay away from systemic toxicities.


PDLLA is poly d- l- lactide acid, and it is a biodegradable polymer that is obtained from the DL lactide. It has a different structure and it is amorphous because it has randomly repeating L-lactide and D-lactide units. It works well as a coating and it degrades faster than other polymer blends. It has a slower release of drugs from the nanoparticles, which helps to avoid overdosing.


PLGA is an acronym used to describe poly D L-lactic co-glycolic acid. It is obtained by the ring opening co-polymerization of glycolide and lactide as monomers. It is considered one of the best-defined biomaterials available for drug delivery in terms of design and performance. It can be used to deliver nanoparticles in cancer treatments through tumor-targeted drug therapy. In addition, it is used for therapeutic agents, including the following:

  • Chemotherapy
  • Antibiotics
  • Antiseptics
  • Anti-inflammatory drugs
  • Antioxidant drugs
  • Proteins
  • And more

4. PCL

PCL is known as polycaprolactone and it is a biodegradable polyester with a low melting point. It is developed as a controlled drug delivery vehicle for vancomycin and it helps to avoid a second surgery. When this drug is loaded into PCL, it is able to keep its composition as a pure drug. It is also used for drug release and theranostic NP delivery.


PTMC is an acronym for poly trimethylene carbonate. They can deliver microparticles, nanospheres, and micellar nanoparticles effectively loaded with drugs. For example, dexamethasone could be released over a period of between 14 and 60 days. This polymer is biodegradable and it can be used for hydrophilic drugs. They have a flexible and hydrophobic nature, which makes them effective.

Guide for Biodegradable Materials

Guide for Biodegradable Materials

Guide for Biodegradable Materials

There are many different types of biodegradable materials in the market. Few of them are processed naturally in the environment, such as Chitin. Other degradable materials are synthesized chemically.  Through special processes, we could obtain material that meed our requirement. The most used is polylactide series and polycaprolactone.

In this post, we will explain all the details about biodegradable materials.

What Does Biodegradable Material Mean?

According to the Merriam Webster Dictionary, biodegradable means, “capable of being broken down especially into innocuous products by the actions of living things (such as microorganism).”  In 3D printing, this means that the material can break down over time. Using these materials is more environmentally friendly because it reduces carbon emissions and more.

Plastics take many years to degrade, and these biodegradable alternatives are important for the future of the planet. In fact, many governments are taking steps to ban single use plastics. As a result, there is a rise in the development of biodegradable materials used in different ways in three-dimensional printing.

What Makes a Material Biodegradable?

Biodegradable materials are simply materials that will break down quickly into harmless compounds with the action of microorganisms. For example, when you see a leaf fall off a tree, it degrades until there is nothing visible left. Fungi and bacteria break it down into smaller parts, and finally, it is broken down into elements that helped to make it, such as carbon dioxide and oxygen.

Biodegradable materials are made from natural ingredients that can degrade. This is achieved by minimizing the amount of processing the material goes through. The material needs to be plant-based, animal-based, or mineral-based to biodegrade, and how quickly it can do so is determined by how much it has been altered from its original state.

Examples of Biodegradable Materials

1.PLLA (poly-l lactide)

Poly-L Lactide is a biodegradable polymer that is often used in medical devices and pharmaceutical applications. It can be used to fabricate resorbable medical devices that degrade over time in physiological conditions.

This material is one of the easiest and most affordable polymers to use for this application. For example, they can be used to make a coronary stent and for bone tissue engineering. PLLA is able to degrade into lactic acid and breaks down over six months to two years in the human body. This makes it a great material for medical implants, including screws, plates, pins, and rods.

2. PDLLA (poly-d l-lactic acid)

PDLLA is a polymer obtained from the DL lactide, and it has a different structure from polymers obtained using only the L-lactide or the D-lactide. It is considered to be amorphous because the polymer is composed randomly of the repeating L-lactide and D-lactide units. It is mainly applied as dental devices or coatings.

PDLLA does not show a melting point, and it can be used as the coating for a suture. It is known to degrade faster than other polymer blends.

3. PCL (polycaprolactone)

Polycaprolactone is a biodegradable polyester that has a low melting point of close to 60 degrees Celsius. Its glass transition temperature is -60 degrees Celsius, and it is resistant to water, oil, solvents, and more. It is degraded by hydrolysis, and it can be used as a biodegradable implant material for the human body. It is successfully used in facial implants and other applications. It can also be used in targeted drug delivery.

4. PLGA (poly lactic co glycolic acid)

PGLA is obtained by the ring-opening co-polymerization of glycolide and lactide as monomers. Lactide has three optical isomers, so the copolymer is glycolide and L-Lactide is abbreviated to PLGA. Its primary use is as an absorbed suture. PGLA, with its higher content of glycolide.

PLGA is rigid and less flexible, which makes it good for drug delivery, stents, sutures, and more. It is a biodegradable and absorbable polymer.

5. PGA (polyglycolide)

PGA is a polymer that is obtained by the ring-opening polymerization of glycolide as a monomer. It is a synthetic braided polymer, and it does a good job of resisting infections from contaminating bacteria. It also retains at least 50% of its tensile strength over 25 days, which makes it good for sutures of the subcutaneous tissue. It is a tough fiber forming polymer that has also been used in the food packaging industry.

6. PTMC (poly trimethylene carbonate)

PTMC are polymers that work well for soft tissue regeneration and drug delivery. It is studied widely because it has a slow degradation time, which extends its lifetime and ends up with fewer adverse reactions inside the body. As a suture, it shows good handling and tying characteristics. It is also ideal for sutures under the skin because it can maintain closure of the skin long enough to give it time to heal.

7. PPDO (poly-p dioxanone)

PPDO is a polymer that is biodegradable, and it is used for drug delivery and sutures. It is also used for absorbable medical devices, including sutures. It is sufficient to use as a suture, a stent, an adhesion barrier, or reinforcement for an adhesion barrier. It is obtained by the ring opening polymerization of p-dioxanone. It is a multifilament, and it also works in pediatric cardiovascular procedures and other tissues that are still growing.

What Is Biodegradable Material Usually Made of?

1. Suture

In the past, sutures were placed in the skin, and they needed to be removed. Biodegradable materials have made it possible to make different sutures that can be absorbed by the body. They hold their integrity long enough to allow the body to heal, and then, they will biodegrade. You can use PLGA and PGA for sutures in subcutaneous tissue. In addition, PTMC works well for sutures under the skin that hold tissue together. PPDO works for deep tissues as well, especially in children as it works with tissue that is still growing.


Stent is placed into the artery to keep it open. Several of these biodegradable materials are excellent choices for this process. You can use PLLA as a coronary stent. PLGA and PGS are good materials for stents and are known to be resistant to infection. Being able to use these biodegradable materials have opened up new doors in the medical field.


3D printed biodegradable bone implants are able to help heal fractures and breaks, as well as other items. They can help support broken bones as they heal. For example, PLLA is used to make screws, rods, pins, and more, which are critical to healing a broken or fractured PDLLA is also used for bone plates and screws.

PCL is useful for helping the tissue around the bone to heal.

4. 3D Printing

3D printing is the process where you make a three-dimensional object from a digital file. You can use all different materials to print the object, including those listed above. When the computer tells the printer what to create, the filament comes out in layers. The 3D object is made once all of the layers are finished.

The biodegradable materials above have led to breakthrough discoveries in the medical field because sutures, stents, and devices to help bone repair can all be made via 3D printing using the biodegradable materials above.

All about Dissolvable Sutures You should Know

All about Dissolvable Sutures You should Know

All about Dissolvable Sutures You should Know

We’ve come a long way since the very first stitches, which were essentially just sewing thread and a needle. Today, stitches, or sutures as they are also called, are more sophisticated than ever and in fact, they include dissolvable sutures that don’t even require a second trip back to the doctor’s office to be removed.

What Are They Made Out of?

Sutures that automatically dissolve instead of having to be removed by a doctor are convenient for many reasons, and the way they work is simple. Basically, these sutures are made out of special materials that dissolve and absorb into the skin, which is why they are also called absorbable stitches.

Conveniently, absorbable sutures can be used on both internal and external wounds, which means they are often used for surgical incisions as well as wounds that aren’t as deep.

Just what are they made out of? Dissolvable stitches are made out of both natural materials such as silk, hair, and collagen, which usually comes from animal intestines; as well as synthetic materials that break down in the body.

Occasionally, part of the suture will not dissolve, but more often than not, the entire stitch dissolves slowly over time and usually is finished by the time the wound is completely healed.

Main Features of Absorbable Sutures

Dissolvable stitches differ from standard stitches in a few ways, the main one being that they are naturally absorbed by the body. In normal situations, your body reacts to anything it considers a foreign substance by trying to destroy it. When you have dissolvable stitches, this “foreign” object creates an inflammatory reaction in the body that automatically and naturally begins to dissolve and absorb them.

Absorbable stitches are also temporary. When you receive regular stitches, they remain there until they are physically removed by a doctor or nurse.

Absorbable stitches only stay on the body for a certain length of time and then they’re gone. The amount of time the stitches take to dissolve varies depending on what they’re made of, their size, and the type of wound they’re covering, but all of them eventually will disappear after being absorbed into the body.

How Do Dissolvable Sutures Work?

Dissolvable sutures break down in the body beginning almost immediately because of the materials they are made of, which is often a type of polyglycolic acid (PGA) or polylactic acid (PLA), both of which usually come from a biomaterial such as starch. These materials do not do well in water and, therefore, they will break down and immediately start to dissolve and absorb into the body.

This usually works because the cells in the skin work to dissolve the stitches naturally as your body is healing. Most absorbable stitches are made to last anywhere from one week to several months, and your doctor will choose the one that best suits your needs.

When Are Dissolvable Stitches Used?

Dissolvable stitches are used on all types of wounds, both external and internal, and one of their biggest advantages is that they do not leave any scarring, which is important to most patients. Some of the types of procedures that can accommodate these absorbable stitches include:

  • Caesarian deliveries, although there are pros and cons to this so not all doctors use it
  • Oral surgery, especially for tooth extractions
  • Orthopedic surgeries such as knee replacements, although it is often used in conjunction with non-dissolvable stitches
  • Removal of breast cancer tumors, mostly because they leave less scarring

All types of wounds and incisions can take these absorbable stitches, but since only a doctor can make the final decision, it is advisable to consult with your physician before you have surgery so that the right choice can be made.

How Long Does It Take for the Sutures to Dissolve?

Most dissolvable sutures last from seven days to several months, and a lot of things can affect that timeframe. These things include:

  • The type of wound or surgical procedure you’ve endured
  • The materials used in the sutures
  • The overall thickness of the sutures

Sometimes, dissolvable stitches will start to absorb in as little as three days, and some are completely dissolved within two weeks. Another factor that affects the absorption rate is the patient’s body characteristics because let’s face it, no two people are exactly alike.

You may have the same body type as someone else and have the same type of surgical procedure yet have completely different timeframes when it comes to how long it takes for your absorbable sutures to dissolve. That being said, the average for these types of stitches to completely dissolve is roughly two to four weeks, sometimes a bit longer.

What to Do If You See a Stray or Loose Stitch

Sometimes, you may see a stray or loose stitch coming from your sutures, and they usually look like small, very thin strings. If this happens, you should immediately contact your doctor, who will tell you exactly what to do.

Some of what you’re experiencing may be completely normal, while some of it may be something to be concerned about. Only your doctor will know for sure.

Just so you know, most problems with dissolvable stitches are caused by not taking proper care of the incision site. Make sure you keep the site clean and dry, and never put any ointment or cream on it unless directed to by your physician.

In addition, don’t scratch or pick at the site, because it can become irritated and swollen.

Allergic Reactions to Dissolvable Stitches

First of all, there is a difference between an allergy and a reaction. Just because you react to your dissolvable sutures doesn’t mean you have an allergy to them.

If you have an allergy to any type of material, you should let your doctor know before the surgery so that only the right types of sutures are used.

In the meantime, you should know that if you experience any type of redness, swelling, pain or tenderness, or oozing liquid from your sutures, you should let the doctor know immediately. Only a qualified physician can determine if the problem is just a reaction to something or a full-blown allergic reaction.