Reactive · Hydrogel-Forming Copolymer
Poly(NHSMA-co-HEMA)
Also written P(NHSMA-co-HEMA), NHSMA-HEMA copolymer | Custom composition — no single CAS
A random copolymer of N-hydroxysuccinimide methacrylate (NHSMA) and 2-hydroxyethyl methacrylate (HEMA). HEMA makes up the majority of the chain, forming the same hydrophilic, biocompatible matrix behind contact lenses and biomedical hydrogels; NHSMA is included as a minor, sparsely distributed comonomer, each unit carrying a reactive NHS ester. The result is a hydrogel-forming scaffold that stays “conjugation-ready” — couple the NHS sites to a growth factor, peptide, antibody, or drug and crosslink the rest into a bioactive hydrogel network.
- Moisture-sensitive — shipped and stored desiccated
Custom composition
(C₈H₉NO₄)ₘ-co-(C₆H₁₀O₃)ₙ
Poly(NHSMA-co-HEMA)
Appearance: White to off-white powder
Character: Hydrogel-forming + amine-reactive
Architecture: Random copolymer
Storage: −20 °C, desiccated, dark
ISO 9001:2015
Manufactured under certified quality management
Custom NHSMA:HEMA Ratio
Reactive-site density tuned independently of matrix hydration
Batch-Level COA
Mn, Đ, composition, and NHS-ester activity per lot
Desiccated Cold-Chain Packaging
Preserves NHS-ester reactivity in transit and storage
CAS No.
Composition-dependent
Molecular Formula
(C₈H₉NO₄)ₘ-co-(C₆H₁₀O₃)ₙ
Character
Hydrogel-forming + amine-reactive
Mn Range
10K – 120K
Form
Powder
A hydrogel matrix with a few reactive handles
HEMA and NHSMA aren't playing the same role here — one is the bulk material, the other is a sparse functional handle riding on top of it.
HEMA: the hydrogel majority
The pendant hydroxyl group hydrates the network and is biocompatible enough for contact lenses on its own — it forms the swollen, water-retentive matrix.
NHSMA: the sparse reactive minority
Each NHS ester reacts with a primary amine to install exactly one growth factor, peptide, or biomolecule per site — a small fraction of units is usually enough.
Ratio protects hydrogel character
Keeping NHSMA content low preserves a stable, predictable HEMA network; too much reactive comonomer starts to change hydration and mechanics.
Couple, then crosslink
A common workflow is to react the NHS sites with your target biomolecule first, then crosslink the modified polymer into a hydrogel network.
Most reactive-hydrogel designs in the literature sit in the 2–15 mol% NHSMA range — enough reactive sites for practical bioconjugation density without materially changing the hydrogel's swelling and mechanical behavior versus a standard HEMA network.
Values below are representative for this monomer pair. Batch-specific COAs with GPC, composition, and NHS-ester activity data are available on request.
| Chemical Name | Poly(N-hydroxysuccinimide methacrylate-co-2-hydroxyethyl methacrylate) |
|---|---|
| Synonyms | P(NHSMA-co-HEMA) · NHSMA-HEMA copolymer · Reactive hydrogel copolymer |
| Monomer Units | N-hydroxysuccinimide methacrylate (NHSMA) · 2-hydroxyethyl methacrylate (HEMA) |
| Architecture | Random (statistical) copolymer — not block or graft |
| NHSMA : HEMA Ratio | Custom / composition-dependent — commonly 2:98 to 20:80 mol% |
| Reactive Group | N-hydroxysuccinimide (NHS) active ester on NHSMA units, reacts with primary amines |
| CAS Number | Not applicable — composition-specific random copolymers are not assigned a single CAS RN |
| Molecular Weight (Mn) | Custom synthesis, typically 10,000–120,000 g/mol |
| Dispersity (Đ) | 1.1–1.3 (RAFT/ATRP) · broader for free-radical routes |
| Appearance | White to off-white powder |
| Solubility | DMF, DMSO, and dry organic solvents for coupling; limited aqueous stability due to NHS-ester hydrolysis |
| Reactivity Note | Hydrolytically unstable in water — dissolve and react promptly; avoid primary-amine buffers |
| Storage | Sealed, desiccated, −20 °C, protected from light and moisture |
Need a specific NHSMA:HEMA ratio, or the polymer pre-coupled to your biomolecule? Talk to technical sales →
Choose the reactive-site density that fits your hydrogel
NHSMA:HEMA feed ratio sets how many reactive sites are available per chain, and how much that trades off against standard hydrogel behavior
NHSMA : HEMA ≈ 2:98
HEMA-dominant
Behaves close to a standard HEMA hydrogel matrix with just enough reactive sites for sparse bioactive functionalization.
NHSMA : HEMA ≈ 10:90
Balanced
A common working range for tissue-engineering scaffolds — meaningful conjugation density while retaining predictable hydrogel swelling.
NHSMA : HEMA ≈ 20:80
Reactive-rich
Applications
Bioactive tissue-engineering scaffolds
Growth factors or adhesion peptides covalently coupled through the NHS sites, then crosslinked into a HEMA hydrogel scaffold.
Functionalized contact lens materials
Builds on HEMA's proven ophthalmic biocompatibility while adding covalently attached drugs or lubricating ligands.
Bioactive wound dressings
Antimicrobial peptides or growth factors immobilized within a moisture-retentive HEMA hydrogel network.
Molecularly imprinted hydrogels
Reactive sites allow covalent anchoring of recognition elements within a hydrophilic, biocompatible HEMA matrix.
Drug-eluting hydrogel implants
Amine-bearing drugs covalently coupled for sustained, diffusion-controlled release from the swollen hydrogel network.
Hydrogel biosensor matrices
A hydrated, permeable HEMA scaffold with covalently anchored capture biomolecules near an embedded transducer.
Cell-adhesive hydrogel surfaces
RGD or other adhesion peptides covalently coupled at defined density to control cell attachment on an otherwise inert HEMA gel.
Reactive dental/biomedical composites
HEMA is a standard dental-material monomer; NHS sites allow covalent attachment of functional or antimicrobial modifiers.
Data & safety documents
Batch-specific COAs with GPC, composition (¹H-NMR), and NHS-ester activity data available for order confirmations. Contact us for a specific lot number.
Safety Data Sheet
GHS-format · EN / ZH
Certificate of Analysis
Ratio + Mw confirmation
Amine Coupling Protocol
Recommended buffers & conditions
FAQ
Most frequent questions and answers
It’s used wherever you need a biocompatible, hydrophilic hydrogel matrix that still needs to carry something specific — a growth factor, peptide, antibody, or drug. The HEMA background keeps the material hydrated and biocompatible, while the sparse NHS sites let you covalently attach a bioactive component before or after gelation.
HEMA units are the hydrogel workhorse — a non-ionic, hydrophilic pendant hydroxyl group that hydrates the network and gives it its biocompatibility. NHSMA units are a minor, reactive comonomer — each carries an NHS ester that reacts with a primary amine. Combining them gives a standard hydrogel matrix that isn’t a dead end: it still has a defined way to attach a bioactive molecule.
NHSMA is typically kept to a small minority — commonly 2–20 mol% — so the HEMA background still dominates the network’s overall swelling and mechanical behavior. Higher NHSMA content gives more reactive sites per chain but starts to shift hydration and network properties away from a standard HEMA hydrogel.
No — HEMA units don’t carry primary amines or otherwise compete for the NHS ester, so they’re chemically inert to the coupling reaction itself. The main practical consideration is the same as for any NHS-ester chemistry: work in an amine-free buffer and avoid excess water exposure before coupling.
Like the HEMA homopolymer story, the linear copolymer as supplied is water-soluble or swellable rather than a fixed network. A typical workflow is to first couple your amine-bearing biomolecule to the NHS sites, then crosslink the modified polymer — often with a difunctional agent such as EGDMA — into an insoluble, swelling hydrogel.
Dissolve the polymer fresh in a dry organic solvent (or briefly in a cold, amine-free aqueous buffer, pH 7.5–8.5) and add your amine-bearing target promptly — protein, peptide, or small molecule. The amine displaces the NHS leaving group to form a stable amide bond at each reacted site.
No — composition-specific random copolymers like this one are not assigned a single CAS Registry Number, since the NHSMA:HEMA ratio, Mn, and dispersity are set per synthesis batch. Each lot’s COA documents the actual composition and NHS-ester activity.
Store sealed, desiccated, at −20 °C, protected from light and moisture — the NHS ester is sensitive to both heat and humidity. Allow the container to reach room temperature before opening, dissolve fresh, and react promptly for best coupling efficiency.