Search

Poly(ether ether ketone) (PEEK) is a semi-crystalline thermoplastic with excellent mechanical and chemical properties. PEEK exhibits a high degree of resistance to thermal, chemical, and bio-degradation. PEEK is used as biomaterial in the field of orthopaedic and dental implants; however, due to its intrinsic hydrophobicity and inert surface, PEEK does not effectively support bone growth. Therefore, new methods to modify PEEK’s surface to improve osseointegration are key to next generation polymer implant materials. Unfortunately, PEEK is a challenging material to both modify and subsequently characterize thus stymieing efforts to improve PEEK osseointegration. In this manuscript, we demonstrate how surface-initiated atom transfer radical polymerization (SI-ATRP) can be used to modify novel PEEK microparticles (PMP). The hard core-soft shell microparticles were synthesized and characterized by DLS, ATR-IR, XPS and TEM, indicating the grafted materials increased solubility and stability in a range of solvents. The discovered surface grafted PMP can be used as compatibilizers for the polymer-tissue interface.

Due to their capacity to conduct complex organic transformations, enzymes find extensive use in medical and industrial settings. Unfortunately, enzymes are limited by their poor stability when exposed to harsh non-native conditions. While a host of methods have been developed to stabilize enzymes in non-native conditions, recent research into the synthesis of polymer-enzyme biohybrids using reversible deactivation radical polymerization approaches has demonstrated the potential of increased enzymatic activity in both native and non-native environments. In this manuscript, we utilize the enzyme lipase, as a model system, to explore the impact that modulation of grafted polymer molecular weight has on enzyme activity in both aqueous and organic media. We studied the properties of these hybrids using both solution-phase enzyme activity methods and coarse-grain modeling to assess the impact of polymer grafting density and grafted polymer molecular weight on enzyme activity to gain a deeper insight into this understudied property of the biohybrid system.

The power of chemical light generation (chemiluminescence) is used to drive polymerization reactions. A biphasic reaction is developed such that light-generating reactions are confined to the organic phase and photopolymerization occurs in the aqueous phase. Well-defined RAFT-capped polymers are synthesized and the kinetics are shown to be dictated by light generation.

A predictable and reproducible number of sulfuric acid sites have been achieved for cation exchange resins by employing a mild SuFEx-based reagent system to effect the hydrolysis of fluorosulfonated polymer beads. The resultant poly(hydrogen sulfate) beads effectively demonstrate their utility as cation exchange resins in ion-capture experiments. Furthermore, their polyfluorosulfonated precursors have also proven to be suitable substrates for traditional SuFEx-type click reactions in both small molecule and protein immobilization applications.

Protein polymer hybrids play an increasingly important role in therapeutics and biocatalysis. Synthesis of these biohybrids can be achieved by either the grafting-from or grafting-to strategy and are generally thought to be interchangeable. Therefore, when choosing between these two strategies the decision is usually based on polymer accessibility and purification preference. However, in this study, we demonstrated that the choice of the polymer ligation strategy played a significant role in the stability and bioactivity of the final hybrid. Our goal was to prepare a thermally stable DNase I polymer hybrid by utilizing either synthetic strategies. We found that the grafting-from strategy using reversible addition-fragmentation chain transfer polymerization (RAFT) or atom transfer radical polymerization (ATRP) yielded DNase I biohybrids with no activity. Control reactions were used to demonstrate inherent protein deactivation caused by the grafting-from conditions for either ATRP or RAFT polymerization. The grafting-to method yielded active and thermally stable DNase I biohybrids.

We report the synthesis of new polymer-protein conjugates using a grafting-from method employing photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. Lipase, an industrially important enzyme, was modified with a reversible addition-fragmentation (RAFT) chain transfer agent (CTA) using activated ester chemistry. To study the effects of polymer composition and molecular weight on the enzyme activity, a hydrophilic and hydrophobic polymer were grafted at three different polymer lengths. We found a significant impact of polymer composition on enzyme activity with hydrophobic polymer substantially increasing enzyme activity.

Protein–polymer hybrids are used in a variety of fields including catalysis, detection, and therapeutics. The grafting-from method for the synthesis of these biohybrids has gained popularity due to the ease of synthesis and purification. In this method, an initiator or chain transfer agent (CTA) is ligated onto an amino acid residue, typically lysine or cysteine, and polymers are subsequently grown in situ. In this manuscript, we report the preparation of protein polymer hybrids by grafting-from a previously overlooked acidic amino acid residue (glutamic and aspartic acid) and compare our results to protein polymer hybrids, grafted from the traditional lysine residue. Herein, we conjugated an atom transfer radical polymerization (ATRP) initiator to acidic amino acid residues and lysine residues and grew polymers from Thermomyces lanuginosa lipase (TL). N-[3-(N,N-Dimethylamino)propyl] acrylamide was grafted from the TL initiator, and the enzymatic activity of protein polymer hybrids was compared. We found that the acidic residues are easily modified with multiple ATRP initiators and polymers are readily grown. Additionally, the hybrids grafted from acidic residues demonstrated a 50% increase in enzyme activity compared to those grafted from lysine residues. Moreover, the activity was higher than that of native lipase TL in both cases. The polymers that were grafted-from the acid residues tended to provide the hybrids with a higher activity at elevated temperatures. These results point to a new amino acid ligation strategy for preparing protein polymer hybrids via a grafting-from method.

The targeted delivery of polymers to neurons is a challenging yet important goal for polymer based drug delivery. We prepared a fentanyl based atom transfer radical polymerization (ATRP) initiator to target the Mu opioid receptor (MOR) for neuronal targeting. We incorporated our recently discovered rigid acrylate linking group into the initiator to retain a high degree of binding to the MOR and grafted random or block copolymers of poly(oligo(ethylene oxide) methacrylate)-block-(glycidyl methacrylate). Trifluoroethanol promoted amine ring opening of the glycidyl methacrylate was used for post-polymerization modification of the fentanyl initiated polymers to attach a near-infrared fluorescent dye (ADS790WS) or to build a targeted siRNA delivery system via modification with secondary amines. We examined the biocompatibility, cellular internalization, and siRNA binding properties of our polymer library in a green fluorescent protein expressing SY SH5Y neuroblastoma cell-line.

The synthesis of a sulfoxide-based water-soluble polymer, poly(2-(methylsulfinyl)ethyl acrylate) (polyMSEA), a polymeric analogue of DMSO, by atom transfer radical polymerization (ATRP) is reported. Well-defined linear polymers were synthesized using relatively low amounts of copper catalyst (1000 or 100 ppm). Two types of star polymers were synthesized by either an “arm-first” approach or a “core-first” approach using a biodegradable β-cyclodextrin core. The glass transition temperatures of both the linear polymer (16 °C) and star polymer (32 °C) were determined by differential scanning calorimetry (DSC). The lower critical solution temperature (LCST) of poly(MSEA) was estimated to be ca. 140 °C by extrapolating the LCST of a series of copolymers with NIPAM. Cytotoxicity tests revealed that both the linear and star polymers have low toxicity, even at concentrations up to 3 mg/mL.

Titanium (Ti) and its alloys are used in orthopedic and dental implants due to their excellent physical properties and biocompatibility. Although Ti exhibits superior osteoconductive properties compared to those of polymer-based implants, improved bone-on growth properties are required for enhanced surgical outcomes and improved recovery surgical interventions. Herein, we demonstrate a novel surface modification strategy to enhance the osteoconductivity of Ti surfaces through the grafting-from procedure of a reactive copolymer via surface-initiated atom transfer radical polymerization (SI-ATRP). Then, postpolymerization conjugation of the P15 peptide, an osteoblast binding motif, was successfully carried out. Subsequent in vitro studies revealed that the surface modification promoted osteoblast attachment on the Ti discs at 6 and 24 h. Moreover, mineral matrix deposition by osteoblasts was greater for the surface-modified Ti than for plain Ti and P15 randomly absorbed onto the Ti surface. These results suggest that the strategy for postpolymerization incorporation of P15 onto a Ti surface with a polymer interface may provide improved osseointegration outcomes, leading to enhanced quality of life for patients.

Post-polymerization functionalization is a critical tool in preparing functional materials. The critical aspects of post-polymerization reactions are high yields, short reaction times, simple purification, near stoichiometric amounts of reactants, and facile reaction conditions. Polymeric epoxides (i.e. poly(glycidyl methacrylate)) represent an underutilized class of functionalized polymers due to long reaction times, high temperatures, and large excess of reactants to drive the reaction to high conversion in a reasonable time frame. In this manuscript we describe the use of a novel solvent trifluoroethanol (TFE) for the ring opening of amines with poly(glycidyl methacrylate). We demonstrate that TFE gives faster reaction times and higher yields than traditional solvents used for the ring opening reaction. We utilized TFE to prepare dual functionalized polymers that could be “clicked” using strain promoted azide alkyne cycloaddition and an amine-bearing drug ring opening of the polymeric backbone.

Post-polymerization modification of polymer chain-ends is a powerful tool for the preparation of functional materials. “Click” type reactions represent the most prevalent post-polymerization strategies. We applied the recently described sulfur(VI) fluoride exchange reaction to functionalize the chain-ends of four polymers prepared using activators generated by electron transfer atom transfer radical polymerization. Aryl-TBDMS terminated polymers were reacted with aryl sulfurofluoridate compounds with a near quantitative conversion. This research represents the application of a new click type reaction to prepare functional polymers.

Bright signal outputs are needed for fluorescence detection of biomolecules at their native expression levels. Increasing the number of labels on a probe often results in crowding-induced self-quenching of chromophores, and maintaining the function of the targeting moiety (e.g., an antibody) is a concern. Here we demonstrate a simple method to accommodate thousands of fluorescent dye molecules on a single antibody probe while avoiding the negative effects of self-quenching. We use a bottlebrush polymer from which extend hundreds of duplex DNA strands that can accommodate hundreds of covalently attached and/or thousands of noncovalently intercalated fluorescent dyes. This polymer–DNA assembly sequesters the intercalated fluorophores against dissociation and can be tethered through DNA hybridization to an IgG antibody. The resulting fluorescent nanotag can detect protein targets in flow cytometry, confocal fluorescence microscopy, and dot blots with an exceptionally bright signal that compares favorably to commercially available antibodies labeled with organic dyes or quantum dots., Here we demonstrate a simple method to accommodate thousands of fluorescent dye molecules on a single antibody probe while avoiding the negative effects of self-quenching. We use a bottlebrush polymer from which extend hundreds of duplex DNA strands that can accommodate hundreds of covalently attached and/or thousands of noncovalently intercalated fluorescent dyes. The fluorescent bottlebrush polymer is then attached to an antibody via DNA hybridization, resulting in an exceptionally bright immunofluorescent label.

α-Chymotrypsin, a commonly used protease, was modified with well-defined oligomers synthesized by RAFT. The well defined polymers were synthesized based on the monomers N,N-dimethylacrylamide (DMAm) or oligo(ethylene oxide) methyl ether acrylate (OEOA). The polymers were conjugated to free amine groups on chymotrypsin through an in-situ 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling approach. The protein–polymer conjugates retained enzymatic activity, and the higher molecular weight DMAm and OEOA polymer, created protein–polymer conjugates with significantly enhanced stability, presumably due to the high molecular weight polymer preventing autolysis of the α-chymotrypsin.

The use of reversible deactivation radical polymerization (RDRP) methods has significantly expanded the field of bioconjugate synthesis. RDRP procedures have allowed the preparation of a broad range of functional materials that could not be realized using prior art poly(ethylene glycol) functionalization. The review of procedures for synthesis of biomaterials is presented with a special focus on the use of RDRP to prepare biohybrids with proteins, DNA and RNA.

Hydrophilic polymers were attached to lysozyme by a combination of grafting-to and grafting-from approaches using RAFT polymerization. A hydrophilic oligomer was synthesized, and attached to the protein. The protein-oligomer hybrid contained the RAFT end group, enabling chain extension in solution. Lysozyme maintained activity throughout this process.

Covalent attachment of poly(ionic liquid)s (PILs) by click chemistry on glass or silicon (Si) surfaces was performed. Poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (polyVBBI+Tf2N−), and copolymers of polyVBBI+Tf2N− with fluorescein O-methacrylate were synthesized by conducting an atom transfer radical polymerization (ATRP) from initiators containing azide or thioacetate groups. The azide- and thiol-terminated PILs were then successfully grafted onto alkyne and alkene modified glass/Si wafers by thermal azide–alkyne cycloaddition and photoinitiated thiol-ene click reactions, respectively. The modified surfaces were characterized by contact angle measurements and ellipsometry. The fluorescent PIL functionalized surfaces showed strong fluorescence under UV irradiation. This procedure of tethering PILs to substrates also provides an easy way to change the surface hydrophilicity by replacing the anions in the grafted PILs. The present approach could be readily applied for surface modifications with other types of PILs or their copolymers to achieve different functionalities on various surfaces.

Activators regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP) of 2-aminoethyl methacrylate hydrochloride (AMA) was successfully performed for the first time. The polymerizations were conducted at 35 °C in isopropanol (IPA)/water mixtures or pure water, using CuBr2/TPMA (TPMA: tris(2-pyridylmethyl)amine) as a metal catalyst complex with slow feeding of ascorbic acid (AscA) to allow regeneration of the activator species. The reactions showed first-order kinetics with monomer conversion and high monomer conversion (>90%), and controlled polymers (Đ ≈ 1.3) were obtained using optimized conditions. For the first time, as a result of the PAMA’s high chain-end functionality, it was possible to extend the polymer and synthesize a well-defined block copolymer (PAMA-b-POEOMA) (OEOMA: oligo(ethylene oxide) methyl ether methacrylate) by ATRP techniques, using AMA as the first block. PAMA-based nanogels, with potential biomedical applications, were prepared by ARGET ATRP in inverse min...

The combination of polymers with nucleic acids leads to materials with significantly advanced properties. To obviate the necessity and complexity of conjugating two macromolecules, a polymer initiator is described that can be directly covalently linked to DNA during solid-phase synthesis. Polymer can then be grown from the DNA bound initiator, both in solution after the DNA-initiator is released from the solid support as well as directly on the solid support, simplifying purification. The resulting polymer-DNA hybrids were examined by chromatography and fluorescence methods that attested to the integrity of hybrids and the DNA. The ability to use DNA-based supports expands the range of readily available molecules that can be used with the initiator, as exemplified by direct synthesis of a biotin polymer hybrid on solid-support. This method expands the accessibility and range of advanced polymer biohybrid materials.

A facile approach was developed to prepare crosslinked ionic polymer hydrogel films by photo-crosslinking utilizing p-vinylbenzyl trimethylammonium chloride (VBTMACl) or p-vinylbenzyl trimethylammonium hydroxide (VBTMAOH) as the monomer and poly(ethylene oxide) dimethacrylate (PEODMA, Mn = 750) as the crosslinker. The films with different crosslinking degrees (20%, 40%, 60%, 80%, and 100%) were prepared and characterized by swelling measurements, scanning electron microscopy (SEM), UV-visible spectroscopy, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and small-angle X-ray scattering (SAXS). It was found that the mechanical and thermal properties of the films were largely influenced by the contents of the crosslinker in the films. By ion-exchange of the anions in the films with various other anions, the hydrophobicity/hydrophilicity of the films was changed. In addition, fluorescent films were prepared by treatment with fluorescein, and paramagnetic films with FeCl4− as a counter anion showed catalytic activity for Friedel–Crafts alkylation. The ionic films with quaternary ammonium chloride groups displayed antimicrobial activity against Escherichia coli (E. coli) with almost 100% killing efficiency. Multifunctional films with various tunable properties have significant potential for a wide range of applications.

Protein–polymer hybrids are an important class of biomaterials. Described is the preparation of a genetically incorporated a non-canonical amino acid (nCAA) containing an ester linked atom transfer radical polymerization (ATRP) initiator, followed by a controlled “grafting from” polymerization. A Methanococcus jannaschii tyrosyl-tRNA synthetase/tRNA CUA pair was selected to genetically encode p-bromoisobutyryloxymethyl- l -phenylalanine (biF) in response to an amber codon. This biF was directly incorporated into green fluorescent protein (GFP) at residue 134 generating biF-GFP. Activators regenerated by electron transfer (ARGET) ATRP was conducted under biologically relevant conditions to graft well-defined poly(oligo ethylene oxide methacrylate) from the biF-GFP. The biF-GFP retained its biofluorescence properties throughout the polymerization indicating the utility of ARGET ATRP for preparing protein–polymer hybrids. The presence of a base-labile ester bond in the initiator, allowed cleavage of the grafted polymer from the protein and directly analyze their molecular weight and molecular weight distribution using gel permeation chromatography (GPC). The cleaved final polymer had a M n = 27,000 and a molecular weight distribution of M w / M n = 1.27.

Activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) was successfully implemented in aqueous media for the first time. A well-controlled polymerization of oligo(ethylene oxide) methyl ether methacrylate (OEOMA) was conducted with 300 ppm or lower of a copper catalyst and tris(2-pyridylmethyl)amine (TPMA) ligand in the presence of an excess of halide salts. Ascorbic acid was continuously fed into the reaction mixture to regenerate the activator complex. The effects of the halide salt concentration, ligand concentration, feeding rate of the reducing agent, and copper concentration were systematically studied to identify conditions that provide both an acceptable rate of polymerization and good control over the polymer properties. The optimized polymerization conditions provided linear first-order kinetics, linear evolution of the molecular weight with conversion, and polymers with narrow molecular weight distributions (Mw/Mn < 1.3) at high monomer conversions (∼70%) ...

Atom transfer radical polymerization (ATRP) methods were developed in water-based media, to grow polymers from proteins under biologically relevant conditions. These conditions gave good control over the resulting polymers, while still preserving the protein’s native structure. Several reaction parameters, such as ligand structure, halide species, and initiation mode were optimized in water and PBS buffer to yield well-defined polymers grown from bovine serum albumin (BSA), functionalized with cleavable ATRP initiators (I). The CuCl complex with ligand 2,2′-bipyridyne (bpy) provides the best conditions for the polymerization of oligo(ethylene oxide) methacrylate (OEOMA) in water at 30 °C under normal ATRP conditions (I/CuCl/CuCl2/bpy = 1/1/9/22), while the CuBr/bpy complex gave better performance in PBS. Activators generated by electron transfer (AGET) ATRP gave well-controlled polymerization of OEOMA at 30 °C with the ligand tris(2-pyridylmethyl)amine (TPMA), (I/CuBr2/TPMA = 1/10/11). The AGET ATRP react...

The synthesis of a water/plasma soluble, noncytotoxic, "clicked" sugar-derivative of curcumin with amplified bioefficacy in modulating amyloid-β and tau peptide aggregation is presented. Curcumin inhibits amyloid-β and tau peptide aggregation at micromolar concentrations; the sugar-curcumin conjugate inhibits Aβ and tau peptide aggregation at concentrations as low as 8 nM and 0.1 nM, respectively. In comparison to curcumin, this conveniently synthesized Alzheimer's drug candidate is a more powerful antioxidant.

Fluorescein O-methacrylate was copolymerized with n-butyl acrylate by atom transfer radical polymerization in a “grafting from” reaction with a multifunctional linear macroinitiator to form pH responsive fluorescent bottlebrushes. The brush-like structure of the synthesized macromolecules was confirmed through molecular imaging by atomic force microscopy. NMR spectroscopy showed that the fluorescent units were successfully incorporated into the polymer. The synthesized bottlebrushes displayed highly fluorescent properties under basic conditions, yet showed no fluorescence under neutral or acidic conditions. The fluorescence could be turned on and off by changing the pH of the solution. These bottlebrush molecules could have potential applications in molecular imaging.

Azide-terminated poly(tert-butyl acrylate) was synthesized via atom transfer radical polymerization (ATRP). Subsequent deprotection was performed to yield poly(acrylic acid) (PAA) possessing a reactive chain-end. A one-pot sequential amidation of the PAA with the amine derivatives of a near-infrared fluorescent dye (ADS832WS) and glucose produced NIRF dye-incorporated water-soluble copolymers. End-group modifications were performed to produce alkyne/biotin-terminated copolymers which were further employed to generate dye-incorporated polymer-protein hybrids via the biotin-avidin interaction with avidin or "click" bioconjugation with azide-modified BSA. We have overcome two fundamental limitations in the synthesis of bioconjugates: (a) the basic restriction in the diversity of copolymers which can be synthesized for producing bioconjugates, (b) the limitation in the number of dyes/drug molecules that can be attached per protein molecule. The copolymers possessed enhanced optical properties compared to the dye due to increased solubility in water. Potential utility of these copolymers and conjugates in multiwell plate based assays, cell surface imaging and in vivo animal imaging were explored.

We demonstrate a simple bioconjugate polymer system that undergoes reversible self-assembling into extended fibrous structures, reminiscent of those observed in living systems. It is comprised of green fluorescent protein (GFP) molecules linked into linear oligomeric strands through click step growth polymerization with dialkyne poly(ethylene oxide) (PEO). Confocal microscopy, atomic force microscopy, and dynamic light scattering revealed that such strands form high persistence length fibers, with lengths reaching tens of micrometers, and uniform, sub-100 nm widths. We ascribe this remarkable and robust form of self-assembly to the cooperativity arising from the known tendency of GFP molecules to dimerize through localized hydrophobic patches and from their covalent pre-linking with flexible PEO. Dissipative particle dynamics simulations of a coarse-grained model of the system revealed its tendency to form elongated fibrous aggregates, suggesting the general nature of this mode of self-assembly.

This invention pertains to methods for producing homogeneous recombinant proteins that contain polymer initiators at defined sites. The unnatural amino acid, 4-(2′-bromoisobutyramido)phenylalanine of formula 1, was designed and synthesized as a molecule comprising a functional group further comprising an initiator for an atom-transfer radical polymerization (‘ATRP”) that additionally would provide a stable linkage between the protein and growing polymer. We evolved a Methanococcus jannaschii (Mj) tyrosyl-tRNA synthetase/tRNACUA pair to genetically encode this unnatural amino acid in response to an amber codon. To demonstrate the utility of this functional amino acid, we produced Green Fluorescent Protein with the unnatural amino acid initiator of formula 1 site-specifically incorporated on its surface (GFP-1). Purified GFP-1 was then used as an initiator under standard ATRP conditions with oligo(ethylene oxide)monomethyl ether methacrylate, efficiently producing a polymer-GFP bioconjugate wherein the polymer is connected at a specifically selected site on GFP.

Protein–polymer hybrids (PPHs) represent an important and rapidly expanding class of biomaterials. Typically in these hybrids the linkage between the protein and the polymer is covalent. Here we describe a straightforward approach to a noncovalent PPH that is mediated by DNA. Although noncovalent, the DNA-mediated approach affords the highly specific pairing and assembly properties of DNA. To obtain the protein–DNA conjugate for assembly of the PPH, we report here the first direct copper catalyzed azide–alkyne cycloaddition-based protein–DNA conjugation. This significantly simplifies access to protein–DNA conjugates. The protein–DNA conjugate and partner polymer–DNA conjugate are readily assembled through annealing of the cDNA strands to obtain the PPH, the assembly of which was confirmed via dynamic light scattering and fluorescence spectroscopy.

Polymer biomolecule hybrids represent a powerful class of highly customizable nanomaterials. Here, we report star-polymer conjugates with DNA using a "ligandless" Cu(I) promoted azide-alkyne cycloaddition click reaction. The multivalency of the star-polymer architecture allows for the concomitant conjugation of other molecules along with the DNA, and the conjugation method provides control over the DNA orientation. The star-polymer DNA nanoparticles are shown to assemble into higher-order nanoassemblies through hybridization. Further, we show that the DNA strands can be utilized in controlled disassembly of the nanostructures.

Curcumin, the primary active ingredient in the spice turmeric, was converted to reactive monofunctional derivatives (carboxylic acid/azide/alkyne). The derivatives were employed to produce a 3 + 2 azide-alkyne "clicked" curcumin dimer and a poly(amidoamine) (PAMAM) dendrimer-curcumin conjugate. The monofunctional curcumin derivatives retain biological activity and are efficient for labeling and dissolving amyloid fibrils. The curcumin dimer selectively destroys human neurotumor cells. The synthetic methodology developed affords a general strategy for attaching curcumin to various macromolecular scaffolds.

This article describes the synthesis of novel well defined polysaccharide–polymer bioconjugates. Alkyne-containing bioconjugates were prepared using Cu(I) catalyzed azide–alkyne [3 + 2] dipolar cycloaddition, i.e. ‘click’ chemistry between an alkyne functionalized low molecular weight heparin (LMWH) and α-azide functionalized stimuli-responsive copolymers synthesized by atom transfer radical polymerization using Activators Generated by Electron Transfer (AGET). The alkyne functionality was incorporated into the heparin by conducting a high yield amidation of the polysaccharide using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The structure and composition of the novel bioconjugates were confirmed by FTIR, NMR and thermogravimetric analysis (TGA).