Investigation of the role of hydrophilic chain length in amphiphilic perfluoropolyether/poly(ethylene glycol) networks: towards high-performance antifouling coatings

The facile preparation of amphiphilic network coatings having a hydrophobic dimethacryloxy-functionalized perfluoropolyether (PFPE-DMA; M(w) = 1500 g mol(-1)) crosslinked with hydrophilic monomethacryloxy functionalized poly(ethylene glycol) macromonomers (PEG-MA; M(w) = 300, 475, 1100 g mol(-1)), intended as non-toxic high-performance marine coatings exhibiting antifouling characteristics is demonstrated. The PFPE-DMA was found to be miscible with the PEG-MA. Photo-cured blends of these materials containing 10 wt% of PEG-MA oligomers did not swell significantly in water. PFPE-DMA crosslinked with the highest molecular weight PEG oligomer (ie PEG1100) deterred settlement (attachment) of algal cells and cypris larvae of barnacles compared to a PFPE control coating. Dynamic mechanical analysis of these networks revealed a flexible material. Preferential segregation of the PEG segments at the polymer/air interface resulted in enhanced antifouling performance. The cured amphiphilic PFPE/PEG films showed decreased advancing and receding contact angles with increasing PEG chain length. In particular, the PFPE/PEG1100 network had a much lower advancing contact angle than static contact angle, suggesting that the PEG1100 segments diffuse to the polymer/water interface quickly. The preferential interfacial aggregation of the larger PEG segments enables the coating surface to have a substantially enhanced resistance to settlement of spores of the green seaweed Ulva, cells of the diatom Navicula and cypris larvae of the barnacle Balanus amphitrite as well as low adhesion of sporelings (young plants) of Ulva, adhesion being lower than to a polydimethyl elastomer, Silastic T2.     

Poly(dimethyl siloxane) (PDMS) network blends of amphiphilic acrylic copolymers with poly(ethylene glycol)-fluoroalkyl side chains for fouling-release coatings. II. Laboratory assays and field immersion trials

Amphiphilic copolymers containing different amounts of poly(ethylene glycol)-fluoroalkyl acrylate and polysiloxane methacrylate units were blended with a poly(dimethyl siloxane) (PDMS) matrix in different proportions to investigate the effect of both copolymer composition and loading on the biological performance of the coatings. Laboratory bioassays revealed optimal compositions for the release of sporelings of Ulva linza, and the settlement of cypris larvae of Balanus amphitrite. The best-performing coatings were subjected to field immersion tests. Experimental coatings containing copolymer showed significantly reduced levels of hard fouling compared to the control coatings (PDMS without copolymer), their performance being equivalent to a coating based on Intersleek 700?. XPS analysis showed that only small amounts of fluorine at the coating surface were sufficient for good antifouling/fouling-release properties. AFM analyses of coatings under immersion showed that the presence of a regular surface structure with nanosized domains correlated with biological performance.     

The development of marine biofilms on two commercial non-biocidal coatings: a comparison between silicone and fluoropolymer technologies

The antimicrobial performance of two fouling-release coating systems, Intersleek 700® (IS700; silicone technology), Intersleek 900® (IS900; fluoropolymer technology) and a tie coat (TC, control surface) was investigated in a short term (10 days) field experiment conducted at a depth of ca 0.5 m in the Marina Bandar Rawdha (Muscat, Oman). Microfouling on coated glass slides was analyzed using epifluorescence microscopy and adenosine-5′-triphosphate (ATP) luminometry. All the coatings developed biofilms composed of heterotrophic bacteria, cyanobacteria, seven species of diatoms (2 species of Navicula, Cylindrotheca sp., Nitzschia sp., Amphora sp., Diploneis sp., and Bacillaria sp.) and algal spores (Ulva sp.). IS900 had significantly thinner biofilms with fewer diatom species, no algal spores and the least number of bacteria in comparison with IS700 and the TC. The ATP readings did not correspond to the numbers of bacteria and diatoms in the biofilms. The density of diatoms was negatively correlated with the density of the bacteria in biofilms on the IS900 coating, and, conversely, diatom density was positively correlated in biofilms on the TC. The higher antifouling efficacy of IS900 over IS700 may lead to lower roughness and thus lower fuel consumption for those vessels that utilise the IS900 fouling-release coating.     

Combinatorial materials research applied to the development of new surface coatings IX: An investigation of novel antifouling/fouling-release coatings containing quaternary ammonium salt groups

Polysiloxane coatings containing chemically-bound (“tethered”) quaternary ammonium salt (QAS) moieties were investigated for potential application as environmental-friendly coatings to control marine biofouling. A combinatorial/high-throughput approach was applied to the investigation to enable multiple variables to be probed simultaneously and efficiently. The variables investigated for the moisture-curable coatings included QAS composition, ie alkyl chain length, and concentration as well as silanol-terminated polysiloxane molecular weight. A total of 75 compositionally unique coatings were prepared and characterized using surface characterization techniques and biological assays. Biological assays were based on two different marine microorganisms, a bacterium, Cellulophaga lytica and a diatom, Navicula incerta, as well as a macrofouling alga, Ulva. The results of the study showed that all three variables influenced coating surface properties as well as antifouling (AF) and fouling-release (FR) characteristics. The incorporation of QAS moieties into a polysiloxane matrix generally resulted in an increase in coating surface hydrophobicity. Characterization of coating surface morphology revealed a heterogeneous, two-phase morphology for many of the coatings investigated. A correlation was found between water contact angle and coating surface roughness, with the contact angle increasing with increasing surface roughness. Coatings based on the QAS moiety containing the longest alkyl chain (18 carbons) displayed the highest micro-roughness and, thus, the most hydrophobic surfaces. With regard to AF and FR properties, coatings based on the 18 carbon QAS moieties were very effective at inhibiting C. lytica biofilm formation and enabling easy removal of Ulva sporelings (young plants) while coatings based on the 14 carbon QAS moities were very effective at inhibiting biofilm growth of N. incerta.     

Combinatorial materials research applied to the development of new surface coatings XVI: fouling-release properties of amphiphilic polysiloxane coatings

High-throughput methods were used to prepare and characterize the fouling-release (FR) properties of an array of amphiphilic polysiloxane-based coatings possessing systematic variations in composition. The coatings were derived from a silanol-terminated polydimethylsiloxane, a silanol-terminated polytrifluorpropylmethylsiloxane (CF₃-PDMS), 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane (TMS-PEG), methyltriacetoxysilane and hexamethyldisilazane-treated fumed silica. The variables investigated were the concentration of TMS-PEG and the concentration of CF₃-PDMS. In general, it was found that the TMS-PEG and the CF₃-PDMS had a synergist effect on FR properties with these properties being enhanced by combining both compounds into the coating formulations. In addition, reattached adult barnacles removed from coatings possessing both TMS-PEG and relatively high levels of CF₃-PDMS displayed atypical base-plate morphologies. The majority of the barnacles removed from these coatings exhibited a cupped or domed base-plate as compared to the flat base-plate observed for the control coating that did not contain TMS-PEG or CF₃-PDMS. Coating surface analysis using water contact angle measurements indicated that the presence of CF₃-PDMS facilitated migration of TMS-PEG to the coating/air interface during the film formation/curing process. In general, coatings containing both TMS-PEG and relatively high levels of CF₃-PDMS possessed excellent FR properties.     

Bioassays and field immersion tests: a comparison of the antifouling activity of copper-free poly(methacrylic)-based coatings containing tertiary amines and ammonium salt groups

This paper focuses on the activity spectrum of three dimethylalkyl tertiary amines as potential active molecules and the corresponding ammonium salt-based antifouling (AF) paints. Bioassays (using marine bacteria, microalgae and barnacles) and field tests were combined to assess the AF activity of coatings. Bioassay results demonstrated that the ammonium salt-based paints did not inhibit the growth of microorganisms (except the dimethyldodecylammonium-based coatings) and that the tertiary amines were potent towards bacteria, diatoms, and barnacle larvae at non-toxic concentrations (therapeutic ratio, LC₅₀/EC₅₀, < 1). The results from field tests indicated that the ammonium salt-based coatings inhibited the settlement of macrofouling and the dimethylhexadecylammonium-based coatings provided protection against slime in comparison with PVC blank panels. Thus, results from laboratory assays did not fully concur with the AF activity of the paints in the field trial.     

Influence of polyethylene glycol chain length on the physicochemical and biological properties of poly(ethylene imine)-graft-poly(ethylene glycol) block copolymer/SiRNA polyplexes

Polyplexes between siRNA and poly(ethylene imine) (PEI) derivatives are promising nonviral carriers for siRNA. The polyplex stability is of critical importance for efficient siRNA delivery to the cytoplasm. Here, we investigate the effect of PEGylation at a constant ratio ( approximately 50%) on the biophysical properties of the polyplexes. Particle size, zeta potential, and stability against heparin as well as RNase digestion and reporter gene knockdown under in vitro conditions of different siRNA polyplexes were characterized. Stability and size of siRNA polyplexes were clearly influenced by PEI-PEG structure, and high degrees of substitution such as PEI(25k)-g-PEG(550)(30) resulted in large (300-400 nm), diffuse complexes (AFM) which showed condensation behavior only at high N/P ratios. All other polyplexes and the PEI control showed similar sizes (150 nm) and compact structures in AFM, with complete condensation reached at N/P ratio of 3. Stability of siRNA polyplexes against heparin displacement and RNase digestion could be modified by PEGylation. Protection against RNase digestion was highest for PEI(25k)-g-PEG(5k)(4) and PEI(25k)-g-PEG(20k)(1), while siRNA/PEI provided insufficient protection. In knockdown experiments using NIH/3T3 fibroblasts stably expressing beta-galactosidase, it was shown that PEG chain length had a significant influence on biological activity of siRNA. Polyplexes with siRNA containing PEI(25k)-g-PEG(5k)(4) and PEI(25k)-g-PEG(20k)(1) yielded similar efficiencies of ca. 70% knockdown as lipofectamine controls. Confocal microscopy demonstrated enhanced cellular uptake of siRNA into cytosol by polyplexes formation with PEI copolymers. In conclusion, both the chain length and graft density of PEG were found to strongly influence siRNA condensation and stability and hence affect the knockdown efficiency of PEI-PEG/siRNA polyplexes.     

Modification of islet of langerhans surfaces with immunoprotective poly(ethylene glycol) coatings via interfacial photopolymerization

Poly(ethylene glycol) (PEG) has been used previously to alter immune interactions and systemic clearance of therapeutic proteins. We present herein chemical approaches for the conceptually similar treatment of therapeutic cells and tissues whereby immune and cell adhesive interactions may be reduced or interrupted, in the context of the transplantation of xenogeneic islets of Langerhans for the treatment of insulin-dependent diabetes mellitus. Visible-light-initiated interfacial photopolymerization of multifunctional PEG-based macromers was performed directly upon the surface of rat islets of Langerhans to produce conformal barrier hydrogel coatings with thickness of order 10 mu;m. The islets continued to be normal in ultrastructure and function as reflected by response to a glucose challenge in vitro. (c) 1994 John Wiley & Sons, Inc.     

Low-pH-sensitive poly(ethylene glycol) (PEG)-stabilized plasmid nanolipoparticles: effects of PEG chain length, lipid composition and assembly conditions on gene delivery

BACKGROUND: We have studied the effects of the poly(ethylene glycol) (PEG) chain length and acyl chain composition on the pH-sensitivity of acid-labile PEG-diorthoester (POD) lipids. The optimal conditions are described for preparation of DNA plasmid encapsulated POD nanolipoparticles (NLPs) which mediate high gene delivery activity in vitro with moderate cytotoxicity. METHODS AND RESULTS: A series of POD lipids with various PEG chain lengths (750, 2000, and 5000 Da) or acyl chains (distearoyl 18:0 or dioleoyl 18:1) were incorporated into DNA containing NLPs or model liposomes as a stealth and bioresponsive component. We investigated the collapse kinetics of the POD-stabilized liposomes when the PEG chain length was changed. We optimized a detergent dialysis method to encapsulate plasmid DNA into NLPs prepared from a mixture of the various POD lipids, cationic lipid and phosphatidylethanolamine lipid. A critical concentration (28 mM) of n-octyl-beta-D-glucopyranoside (OG) enabled high encapsulation of DNA plasmid into 100 nm particles with a neutral surface charge. The POD NLPs are stable at pH 8.5 but rapidly collapse (approximately 10 min) into aggregates at pH 5.0. In the detergent solution there is a metastable DNA-lipid intermediate that evolves into a stable NLP if the detergent is removed shortly after adding DNA to the lipid-detergent mixture. The rank order of transfection activity from NLPs containing PEG-lipid was POD 750 > POD 5000 = POD 2000 > non-pH-sensitive PEG-lipid. The particle size stability was in the reverse order. Binding of the NLPs to cells reached a maximum level by 12 hours. The POD NLPs had slightly less transfection activity but considerably lower cytotoxicity than the PEI-DNA polyplex. CONCLUSIONS: Of the PEG-orthoester lipids tested, POD 2000 is the better choice for the preparation of sterically stabilized NLPs with a small particle diameter, good stability, low cytotoxicity, and satisfactory transfection activity.     

Chemoselectivity and enhanced activity of poly(ethylene glycol)-modified lipases acylating hydrophilic aminoacid derivatives in organic solvents

Summary Lipases, when covalently modified with poly(ethylene grycol), catalyse the acylation of hydrophilic substrates in organic solvents with increase in the reaction rate even in the presence of 4% water. As a further result the modified Lipoprotein lipase from Pseudomonas species acylates only amino group in serine--naphthylamide.     

The conformation of the poly(ethylene glycol) chain in mono-PEGylated lysozyme and mono-PEGylated human growth hormone

Covalent conjugation of poly(ethylene glycol) or "PEGylation" has proven an effective strategy to improve pharmaceutical protein efficacy by hindering recognition by proteases, inhibitors, and antibodies and by retarding renal clearance. Because it determines the strength and range of intermolecular steric forces and the hydrodynamic properties of the conjugates, the configuration of protein-conjugated PEG chains is the key factor determining how PEGylation alters protein in vivo circulation time. Mono-PEGylated proteins are typically described as having a protective PEG shroud wrapped around the protein, but recent dynamic light scattering studies suggested that conjugates adopt a dumbbell configuration, with a relatively unperturbed PEG random coil adjacent to the globular protein. We used small-angle neutron scattering (SANS) to distinguish between the dumbbell model and the shroud model for chicken-egg lysozyme and human growth hormone covalently conjugated to a single 20 kDa PEG chain. The SANS contrast variation technique was used to isolate the PEG portion of the conjugate. Scattering intensity profiles were well described by the dumbbell model and inconsistent with the shroud model.     

Synthesis and self-assembly of chitosan-based copolymer with a pair of hydrophobic/hydrophilic grafts of polycaprolactone and poly(ethylene glycol)

Chitosan-based copolymers with binary grafts of hydrophobic polycaprolactone and hydrophilic poly(ethylene glycol) (CS-g-PCL&PEG) were prepared by a homogeneous coupling reaction of phthaloyl-protected chitosan with functional PCL-COOH and PEG-COOH, following deprotection to regenerate free amino groups back to chitosan backbone. They were characterized by ¹H NMR, Fourier transform infrared and X-ray diffraction analysis. These CS-g-PCL&PEG copolymers could form nano-size self-aggregates in acidic aqueous solution without a specific processing technique, which were investigated using dynamic light scattering and transmission electron microscopy. The formed self-aggregates become smaller with weakened stability upon pH increasing. Moreover, the aggregates of copolymer with higher content of PEG and PCL grafts could remain stable for over 30 days in both acid and neutral condition. A possible mechanism was proposed for the formation of self-aggregates from CS-g-PCL&PEG and their structural changes as pH. It is warranted to find promising application of these self-aggregates based on chitosan as drug carriers.     

Rapid protein anchoring into the membranes of Mammalian cells using oleyl chain and poly(ethylene glycol) derivatives

The cell membrane is an important interface for communication with extracellular events, and incorporation of bioactive substances, such as antibodies and receptors, into the cell membrane may enhance the potential abilities of cells. Gene manipulation, chemical modification of membrane proteins, and cell surface painting using a GPI anchor have been performed to introduce substances into cell membranes. Furthermore, many lipid anchors have also been used to modify lipid membranes such as liposomes. In this study, we have focused on developing an easy and rapid method for anchoring of substances including macromolecular proteins into the membranes of living mammalian cells. We employed a single oleyl chain derivative coupled with hydrophilic poly(ethylene glycol) (PEG90, the ethyleneoxide (EO) unit is 90) to facilitate solubilization in water. This water-soluble derivative was designated Biocompatible Anchor for Membrane (BAM). Some proteins (streptavidin, EGFP and an antibody) were coupled with BAM90 at the distal terminal of PEG and rapidly (within a few minutes) anchored into the membranes of various cells (NIH3T3, 32D, Ba/F3, hybridoma 9E10). However, the anchored BAM90 disappeared from the cell membranes within 4-5 h in serum-free culture media, and moreover, the retention time of anchoring was shortened (1-2 h) in culture medium containing 10% FBS. We further prepared a dioleylphosphatidylethanolamine (DOPE)-PEG derivative (DOPE-BAM80, the EO unit is 80) as a double oleyl chain derivative for comparison with the single oleyl chain derivative, BAM90. The retention time of anchored DOPE-BAM80 was longer than that of BAM90 and more than 8 h in culture media with and without 10% serum. Furthermore, the treatment time of DOPE-BAM80 for anchoring was nearly as short (within a few minutes) as that of BAM90. In addition, both types of BAMs, BAM90 and DOPE-BAM80, showed no cytotoxicity. Therefore, DOPE-BAM80 is useful for protein anchoring to cells. Although the utilization of BAM90 is considered to be limited, it is expected to useful in restricted environments, for example, in tissues such as the cornea, peritoneum, bladder, and various mucosae, which are less exposed to serum. Thus, we suggest the possibility that both types of BAM can be applied to cell surface engineering.     

Marine anti-biofouling efficacy of amphiphilic poly(coacrylate) grafted PDMSe: effect of graft molecular weight

There is currently strong motivation due to ecological concerns to develop effective anti-biofouling coatings that are environmentally benign, durable, and stable for use by the maritime industry. The antifouling (AF) and fouling-release (FR) efficacy of amphiphilic, charged copolymers composed of ~52% acrylamide, ~34% acrylic acid, and ~14% methyl acrylate grafted to poly(dimethyl siloxane) (PDMSe) surfaces were tested against zoospores of the green alga Ulva linza and the diatom Navicula incerta. The biofouling response to molecular weight variation was analyzed for grafts ranging from ~100 to 1,400 kg mol^?1, The amphiphilic coatings showed a marked improvement in the FR response, with a 55% increase in the percentage removal of diatoms and increased AF efficacy, with 92% reduction in initial attachment density of zoospores, compared to PDMSe controls. However, graft molecular weight, in the range tested, was statistically insignificant. Grafting copolymers to PDMSe embossed with the Sharklet? microtopography did not produce enhanced AF efficacy.     

Poly(dimethyl siloxane) (PDMS) network blends of amphiphilic acrylic copolymers with poly(ethylene glycol)-fluoroalkyl side chains for fouling-release coatings. II. Laboratory assays and field immersion trials

Amphiphilic copolymers containing different amounts of poly(ethylene glycol)-fluoroalkyl acrylate and polysiloxane methacrylate units were blended with a poly(dimethyl siloxane) (PDMS) matrix in different proportions to investigate the effect of both copolymer composition and loading on the biological performance of the coatings. Laboratory bioassays revealed optimal compositions for the release of sporelings of Ulva linza, and the settlement of cypris larvae of Balanus amphitrite. The best-performing coatings were subjected to field immersion tests. Experimental coatings containing copolymer showed significantly reduced levels of hard fouling compared to the control coatings (PDMS without copolymer), their performance being equivalent to a coating based on Intersleek 700?. XPS analysis showed that only small amounts of fluorine at the coating surface were sufficient for good antifouling/fouling-release properties. AFM analyses of coatings under immersion showed that the presence of a regular surface structure with nanosized domains correlated with biological performance.     

Electric-field orientation of sodium poly(l-glutamate) in methanol/water and ethylene glycol/water mixtures

Transient electric birefrinqence and circular dichroism measurements have been made on sodium poly(l-glutamate) in methanol/waer and ethylene glycol/water mixtures of various compositions. The specific Kerr constant increased upon the transition from coil to helix, but decreased with further increase in methanol or ethylene glycol content on the helix side.     

Influence of poly(ethylene glycol) grafting density and polymer length on liposomes: Relating plasma circulation lifetimes to protein binding

The incorporation of poly(ethylene glycol) (PEG)-conjugated lipids in lipid-based carriers substantially prolongs the circulation lifetime of liposomes. However, the mechanism(s) by which PEG-lipids achieve this have not been fully elucidated. It is believed that PEG-lipids mediate steric stabilization, ultimately reducing surface-surface interactions including the aggregation of liposomes and/or adsorption of plasma proteins. The purpose of the studies described here was to compare the effects of PEG-lipid incorporation in liposomes on protein binding, liposome-liposome aggregation and pharmacokinetics in mice. Cholesterol-free liposomes were chosen because of their increasing importance as liposomal delivery systems and their marked sensitivity to protein binding and aggregation. Specifically, liposomes containing various molecular weight PEG-lipids at a variety of molar proportions were analyzed for in vivo clearance, aggregation state (size exclusion chromatography, quasi-elastic light scattering, cryo-transmission and freeze fracture electron microscopy) as well as in vitro and in vivo protein binding. The results indicated that as little as 0.5 mol% of 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE) modified with PEG having a mean molecular weight of 2000 (DSPE-PEG₂₀₀₀) substantially increased plasma circulation longevity of liposomes prepared of 1,2-distearoyl-sn-glycero-3-phosphatidylcholine (DSPC). Optimal plasma circulation lifetimes could be achieved with 2 mol% DSPE-PEG₂₀₀₀. At this proportion of DSPE-PEG₂₀₀₀, the aggregation of DSPC-based liposomes was completely precluded. However, the total protein adsorption and the protein profile was not influenced by the level of DSPE-PEG₂₀₀₀ in the membrane. These studies suggest that PEG-lipids reduce the in vivo clearance of cholesterol-free liposomal formulations primarily by inhibition of surface interactions, particularly liposome-liposome aggregation.     

Influence of poly(ethylene glycol) grafting density and polymer length on liposomes: relating plasma circulation lifetimes to protein binding

The incorporation of poly(ethylene glycol) (PEG)-conjugated lipids in lipid-based carriers substantially prolongs the circulation lifetime of liposomes. However, the mechanism(s) by which PEG-lipids achieve this have not been fully elucidated. It is believed that PEG-lipids mediate steric stabilization, ultimately reducing surface-surface interactions including the aggregation of liposomes and/or adsorption of plasma proteins. The purpose of the studies described here was to compare the effects of PEG-lipid incorporation in liposomes on protein binding, liposome-liposome aggregation and pharmacokinetics in mice. Cholesterol-free liposomes were chosen because of their increasing importance as liposomal delivery systems and their marked sensitivity to protein binding and aggregation. Specifically, liposomes containing various molecular weight PEG-lipids at a variety of molar proportions were analyzed for in vivo clearance, aggregation state (size exclusion chromatography, quasi-elastic light scattering, cryo-transmission and freeze fracture electron microscopy) as well as in vitro and in vivo protein binding. The results indicated that as little as 0.5 mol% of 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE) modified with PEG having a mean molecular weight of 2000 (DSPE-PEG(2000)) substantially increased plasma circulation longevity of liposomes prepared of 1,2-distearoyl-sn-glycero-3-phosphatidylcholine (DSPC). Optimal plasma circulation lifetimes could be achieved with 2 mol% DSPE-PEG(2000). At this proportion of DSPE-PEG(2000), the aggregation of DSPC-based liposomes was completely precluded. However, the total protein adsorption and the protein profile was not influenced by the level of DSPE-PEG(2000) in the membrane. These studies suggest that PEG-lipids reduce the in vivo clearance of cholesterol-free liposomal formulations primarily by inhibition of surface interactions, particularly liposome-liposome aggregation.     

Preparation and characterization of poly(ethylene glycol)-g-chitosan with water- and organosolubility

A new scheme was proposed for synthesizing poly(ethylene glycol)-g-chitosan (PEG-g-CS), where methoxy poly(ethylene glycol) iodide (MPEG-I) (M_n 2000) was used for N-substitution of triphenylmethyl chitosan (TPM-CS) in organic medium. The graft copolymers were obtained by subsequent removal of protecting groups with dichloroacetic acid. By varying PEG-I/TPM-CS feed ratio, the grafting levels (GL) of PEG can be adjusted. The chitosan derivatives were characterized by FTIR, ¹H NMR, ¹³C NMR and DSC. All the copolymers were soluble in water over wide pH range. Furthermore, organosolubility of the hybrids in DMF and DMSO was also achieved when the DS value more than 24%. The lysozyme degradation rate of the copolymers in aqueous neutral medium decreased with the increase of GL value.