Bioactive Poly Research Articles

Design and synthesis of biomimetic hydrogel scaffolds with controlled organization of cyclic RGD peptides.

We report on the rational design and synthesis of a new type of bioactive poly(ethylene glycol) diacrylate (PEGDA) macromers, cyclic Arg-Gly-Asp (cRGD)-PEGDA, to mimic the cell-adhesive properties of extracellular matrix (ECM), aiming to create biomimetic scaffolds with controlled spatial organization of ligands and enhanced cell binding affinity for tissue engineering. To attach the cRGD peptide in the middle of PEGDA chain, a tailed cRGD peptide, c[RGDfE(SSSKK-NH2)] (1), was synthesized with c(RGDfE) linked to a tail of SSSKK. The tail consists of a spacer with three serine residues and a linker with two lysine residues for conjugating with acryloyl-PEG-NHS (5) to create cRGD-PEGDA (6). cRGD-PEGDA possesses good photopolymerization ability to fabricate hydrogel scaffolds under UV radiation. Surface morphology and composition analysis demonstrates that cRGD-PEGDA hydrogels were well-constructed with porous three-dimensional (3D) structures and uniform distribution of cRGD ligands. Our results show that cRGD-PEGDA hydrogels facilitate endothelial cell (EC) adhesion and spreading on the hydrogel surfaces and exhibit significantly higher EC population in comparison with linear RGD-modified hydrogels at low peptide incorporation. Since ligand presentation in biomimetic scaffolds plays an important role in controlling cell behavior, cRGD-PEGDA has great advantages of controlling hydrogel properties and ligand spatial organization in the resulting scaffolds. Furthermore, cRGD-PEGDA is an attractive candidate for the future development of tissue engineering scaffolds with optimum cell adhesive strength and ligand density.

Synthesis and bioactivity of poly(HPMA)–lysozyme conjugates: the use of novel thiazolidine-2-thione coupling chemistry

A novel thiazolidine-2-thione functionalized chain transfer agent (CTA) was synthesized and used as a reversible addition-fragmentation chain transfer (RAFT) polymerization agent to prepare well-defined poly-N-(2-hydroxypropyl) methacrylamide (PHPMA). The polymer chains had pre-designed molecular weights, narrow polydispersities and were chain-end functionalized. On incubation with protein (lysozyme) under different pH conditions, PHPMA was conjugated to the protein surface via covalent amide bonding. The bioactivity of the lysozyme-PHPMA conjugates was assessed using Micrococcus lysodeikticus (Ml) cells as substrates. The number of polymer chains attached to the protein could be controlled by both the pH of the conjugation reaction and the molecular weights of the polymers, thereby influencing significantly the bioactivity of the protein-polymer conjugates.

Enhancing growth and proliferation of human gingival fibroblasts on chitosan grafted poly (ε-caprolactone) films is influenced by nano-roughness chitosan surfaces

The bioactivity of poly (epsilon-caprolactone) (PCL) films is improved by grafting chitosan (CS) surfaces with various values of nano-roughness on PCL surfaces. To examine the effects of the design, growing human gingival fibroblasts (HGFs) on the films was conducted. Various values of nano-rough CS surfaces were cast using nano-rough PCL molds that had been fabricated using a solvent-etched technique. The features of nano-CS/PCL surfaces were characterized using an atomic force microscope (AFM) to observe the topography and to determine the value of centerline average roughness of a surface, R(a). The R(a) values of the nano-CS/PCL films were 36.8 +/- 1.6, 100.0 +/- 3.0, and 148 +/- 7.0 nm, while that of the smooth CS/PCL film was 12.5 +/- 1.6 nm. The growth and proliferation of HGFs on the films are elucidated by fluorescent staining and analyzed by MTT viability assay following three and 7 days of culture. The viability assay of the cells reveals that the growth rates of HGFs on both CS/PCL and nano-CS/PCL films significantly exceed (95% or more; P < 0.001) those of PCL on both days, demonstrating the improvement of the bioactivity of PCL films by grafting CS. Additionally, the growth rates and proliferations of HGFs on nano-CS/PCL films of roughness 100 and 148 nm markedly exceed (15% or more; P < 0.001) those on 36.8 nm nano-CS/PCL and CS/PCL films, after both periods of culturing, indicating that the high nano-roughness CS surfaces further enhance the growth rate of HGFs. In conclusion, markedly improving the bioactivity of PCL films by grafting CS is demonstrated. Moreover, high nano-roughness of nano-CS/PCL films can further accelerate the growth and proliferation of HGFs compared with those of CS/PCL films. This work presents a new concept for designing biomaterials in tissue engineering.

Biomimetic hydrogels for biosensor implant biocompatibility: electrochemical characterization using micro-disc electrode arrays (MDEAs)

Our interest is in the development of engineered microdevices for continuous remote monitoring of intramuscular lactate, glucose, pH and temperature during post-traumatic hemorrhaging. Two important design considerations in the development of such devices for in vivo diagnostics are discussed; the utility of micro-disc electrode arrays (MDEAs) for electrochemical biosensing and the application of biomimetic, bioactive poly(HEMA)-based hydrogel composites for implant biocompatibility. A poly(HEMA)-based hydrogel membrane containing polyethylene glycol (PEG) was UV cross-linked with tetraethyleneglycol diacrylate following application to MDEAs (50 mum discs) and to 250 mum diameter gold electrodes within 8-well culture ware. Cyclic voltammetry (CV) of the MDEAs revealed a reduction in the apparent diffusion coefficient of ferrocenemonocarboxylic acid (FcCO(2)H), from 6.68 x 10(-5) to 6.74 x 10(-6) cm(2)/s for the uncoated and 6 mum thick hydrogel coated devices, respectively. Single frequency (4 kHz) temporal impedance measurements of the hydrogels in the 8-well culture ware showed a reversible 5% change in the absolute impedance of the hydrogels when exposed to a pH change between 6.1 to 7.2 and a 20% drop between pH 6.1 and 8.8.

Bioactive poly( L-lactic acid)-chitosan hybrid scaffolds

Poly( L-lactic acid)/Chitosan (PLLA/CHT) hybrid scaffolds were prepared by depositing CHT onto the pore walls in order to form a micro-structured low dense foam inside previously prepared PLLA scaffolds. The morphology and pore architecture of the scaffolds were evaluated by scanning electronic microscopy (SEM) and micro-computational tomography (micro-CT). The microstructure of the CHT fraction depends on its concentration in the solution used to impregnate the PLLA scaffolds. The water-uptake capability of the CHT fraction permitted the production of calcium-phosphate precursors in the structure of the hybrid constructs, on dipping them into alternate phosphorous and calcium solutions. Bioactivity tests, using incubation protocols in a simulated body fluid with ion concentrations approximately equal to those of human blood plasma, allowed the observation of the apatite deposition within the hybrid scaffolds, especially the ones with a higher CHT content. This work shows that bioactive scaffolds, with potential to be used in bone tissue engineering, can be obtained by combining chitosan with PLLA porous structures, following a simple and fast pre-calcification protocol.

Bioactive poly(2‐hydroxyethylmethacrylate)/silica gel hybrid nanocomposites prepared by sol‐gel process

A hybrid of poly(2-hydroxyethylmethacrylate) (pHEMA), a polymer widely employed for biomedical applications, and silica gel, exhibiting a well-known bioactivity, was produced by sol-gel. The amount of the inorganic precursor, tetraethoxysilane (TEOS), was mixed to the organic monomer, so as to have a final concentration of 30% (w/w) of silica gel to the mass of polymer. The nanocomposite was characterized for its composition by thermogravimetric (TG) analysis, swelling behavior, glass transition temperature using differential thermal analysis (DTA), morphology through scanning electron microscopy (SEM), and bioactivity using FT-IR spectroscopy, SEM, and energy dispersive system (EDS). The nanocomposite showed phase separation between the polymer and the silica gel, improved thermal stability and swelling properties and higher glass transition temperature than pHEMA. Moreover, bioactive SiO(2) gel nanoparticles promoted apatite formation on the surface of the modified hydrogel, when it was soaked in SBF. Therefore, the obtained bioactive nanocomposite can be used to make bioactive scaffold for bone engineering.

Preparation of Bioactive Poly(Lactic-Co-Glycolic)Acid and Silica Gel Fibers Mixed Non-Woven Fabric

Poly(lactic-co-glycolic)acid and silica gel fibers mixed non-woven fabric was made by electro-spinning method for the potential application as a bone grafting material. The silica gel, the source material for electro-spinning, was prepared by the hydrolysis of tetraethyl orthosilicate in the presence of calcium salt, water, hydrochloric acid and ethanol. Poly(lactic-co-glycolic)acid solution was prepared by dissolving it in the hexafluoroisopropanol. Then, they were transferred to two separate syringes which were connected to the high voltage supply generating a high electric field between the spinneret and the ground collecting drum. The silica gel containing calcium and poly(lactic-co-glycolic)acid solution were spun together under the electric field of 2 ㎸/㎝. The FE-SEM observations showed that the silica gel and poly(lactic-co-glycolic)acid fibers were mixed together completely and its handling property was much improved compared to that of the non-woven silica gel fabric. After soaking in the SBF for 1 week, low crystalline apatite crystals were also observed to occur on the silica fiber surfaces first and then they were also observed to occur on the poly(lactic-co-glycolic)acid fiber surfaces. From the results, it can be concluded that the poly(lactic-co-glycolic)acid and silica gel fibers mixed non-woven fabric made by electro-spinning method has a bioactivity. It means it has a potential to be used as a bone grafting material because of its apatite-forming ability, high surface area to volume ratio and high porosity.

Bioactive Poly(ethylene terephthalate) Fibers and Fabrics: Grafting, Chemical Characterization, and Biological Assessment

The grafting of poly(sodium styrene sulfonate) (pNaSS) onto ozone-treated poly(ethylene terephthalate) (PET) fabric surfaces was characterized by X-ray photoelectron spectroscopy and toluidine blue colorimetry. Significant amounts of pNaSS were grafted over the range of experimental conditions examined in this study (30-120 min of ozonation, reaction at 65 or 70 degrees C, and reaction times up to 240 min). Within these ranges the amount of grafted pNaSS increased with both ozonation time and reaction temperature. The amount of grafted pNaSS increased over the first 60 min of reaction, then remained relatively constant from 60 to 240 min. For the biological experiments pNaSS-grafted samples were prepared with 30 min of ozonation and 60 min of reaction at a grafting temperature of 70 degrees C. The ozonation time was limited to 30 min to minimize any possible degradation of the PET fabrics by the ozonation treatment. The pNaSS-grafted PET surface adsorbed a factor of 4 more compared to the nongrafted surfaces. The strength of fibroblast adhesion was an order of magnitude higher on pNaSS-grafted PET fabrics compared to that on nongrafted PET fabrics. This difference in the cell attachment was correlated to the cell spreading, which was better and more homogeneous on the grafted fibers compared to the nongrafted fibers. Fibroblasts adhered more strongly on surfaces precoated with normal human plasma compared to surfaces precoated with 10% fetal calf serum in Dulbecco's modified Eagle's medium.

Fabrication of Poly-(DL-Lactic Acid)—Wollastonite Composite Films with Surface Modified β-CaSiO3 Particles

Bioactive poly-(DL-lactic acid) (PDLLA)-wollastonite composite films are successfully fabricated using surface modified wollastonite (m beta-CaSiO 3) particles through solvent casting-evaporation method. The surface modification of beta-CaSiO3 particles are conducted by reaction of the ceramic particles with dodecyl alcohol. Surface morphology, tensile strength, and bioactivity of the composite films are investigated. The results show that the particle distribution and tensile strength of the composite films with modified beta-CaSiO3 particles are significantly improved while the bioactivity is retained. As a result, the maximum tensile strength is enhanced 52.2% when compared with the PDLLA-beta-CaSiO3 composite films prepared using unmodified beta-CaSiO3 particles when the inorganic filler content is 15 wt%. Scanning electron microscopy (SEM) observation suggests that the modified m beta-CaSiO3 particles are homogeneously dispersed in the PDLLA matrix. The bioactivity of the composite films is evaluated by soaking in a simulated body fluid (SBF) and the result suggests that the modified composite film is still bioactive and can induce the formation of HAp on its surface after the immersion in SBF, despite the bonded dodecyl alkyl on the surface of the inorganic particles. All these results imply that the surface modification of beta-CaSiO3 with dodecyl alcohol is an effective approach to prepare PDLLA-beta-CaSiO3 composite with improved properties.

Thermoresponsive and bioactive poly(vinyl ether)-based hydrogels synthesized by radiation copolymerization and photochemical immobilization

A thermoresponsive hydrogel was synthesized by radiation copolymerization of ethylene glycol vinyl ether (EGVE) and butyl vinyl ether (BVE) in the presence of cross-linking agent diethylene glycol divinyl ether. The gel was modified by a cell adhesion factor RGD by photochemical immobilization technique. While the unmodified hydrogel shows fully hydrated form at low temperatures (+4 °C) and it extensively dehydrates at 37 °C, the biomodified hydrogel still kept its thermoresponsive character after immobilization. The effectiveness of immobilization was checked with FTIR-ATR and XPS. The use of bioactive thermoresponsive hydrogels in cell culture applications was investigated. For this purpose, cell culture experiments were realized by L929 mouse fibroblasts. Cell attachment experiments revealed the effect of immobilized RGD with higher values of cell attachment (∼85%), which were obtained especially in the absence of serum. The thermoresponsive character of the hydrogel was useful for the application of low-temperature treatment in order to recover the attached viable cells from the surface of the hydrogel without using trypsin. When the culture temperature was decreased from 37 to 10 °C for 30 min ∼80% of the cells were detached from the hydrogel surface.

Comparative in vitro and in vivo studies using a bioactive poly(ε‐caprolactone)‐organosiloxane nanohybrid containing calcium salt

Comparative in vitro and in vivo studies were conducted using a bioactive poly(epsilon-caprolactone)-organosiloxane nanohybrid containing calcium, which was prepared by sol-gel method. The behavior of human bone marrow stromal cells (hBMSCs) during in vitro osteogenic differentiation were evaluated on poly(epsilon-caprolactone)-organosiloxane nanohybrid and poly(epsilon-caprolactone)-organosiloxane nanohybrid coated with apatite, which mimicked in vivo events. hBMSCs cultured on tissue culture plates (TCPs) were used as a control. For comparative studies, in vivo testing was also conducted using poly(epsilon-caprolactone)-organosiloxane nanohybrid and poly(epsilon-caprolactone)-organosiloxane nanohybrid coated with apatite in the diaphyseal bone defects of rabbit tibiae. Initial attachments and early proliferations of hBMSCs onto poly(epsilon-caprolactone)-organosiloxane with or without the apatite layer were comparable those onto TCPs. However, the late proliferation and the osteogenic differentiation activities on poly(epsilon-caprolactone)-organosiloxane nanohybrid were significantly lower than the hybrid coated with apatite or TCPs. These results were caused by the delayed detachment of hBMSCs induced by the upward growth of spire-shaped apatite granules on the flat apatite layer through mixed nucleation (heterogeneous and homogeneous nucleation) and growth of apatite crystals during cell culture. However, the poly(epsilon-caprolactone)-organosiloxane nanohybrid showed excellent osteoconductivity as same as poly(epsilon-caprolactone)-organosiloxane nanohybrid coated with apatite in vivo even though the cell testing results in vitro were poor. This discrepancy can be explained by the difference in initial degree of supersaturation of apatite in cell culture medium and buffering ability between cell culture medium and body fluid with respect to calcium, which directly affects the nucleation mechanism of apatite crystals and the morphology of grown apatite granules. These findings imply that much attention is required and an optimal method should be used to assess cell responses in vitro. Our results suggest that precoating the apatite layer before in vitro testing is desirable for bioactive materials that release calcium quickly and in large amount because this treatment can more closely mimic in vivo events.

Sol-gel synthesis, characterization and bioactivity of poly(ether-imide)/TiO2 hybrid materials.

Novel organic-inorganic hybrid materials were synthesized by the sol-gel method from a multicomponent solution containing titanium butoxide, 6 weight % (wt%) or 12 wt% poly(ether-imide) (PEI), water and chloroform. The structure of the interpenetrating network is realized by hydrogen bonds between the Ti-OH group (H-donator) in the sol-gel intermediate species and the carboxylic group (H-acceptor) in the repeating units of the polymer. By Fourier transform infrared (FTIR) analysis the presence of hydrogen bonds between organic-inorganic components of the hybrid materials were proved. The morphology of the hybrid materials was studied by scanning electron microscopy (SEM). The structure of a molecular level dispersion was disclosed by an atomic force microscope (AFM), pore size distribution and surface measurements. The AFM and SEM analyzes confirmed that the PEI/TiO2 samples can be considered homogenous organic/inorganic hybrid materials because in both the compositions studied the average domains were less than 400 nm in size. The bioactivity of the synthesized hybrid materials was demonstrated by the formation of a layer of hydroxyapatite on the surface of the PEI/TiO2 samples soaked in a fluid simulating the composition of human blood plasma (SBF), demonstrated by SEM and energy dispersive spectroscopy (EDS) microscopy.

Stereolithography of Three-Dimensional Bioactive Poly(Ethylene Glycol) Constructs with Encapsulated Cells

Stereolithography (SL) was used to fabricate complex 3-D poly(ethylene glycol) (PEG) hydrogels. Photopolymerization experiments were performed to characterize the solutions for use in SL, where the crosslinked depth (or hydrogel thickness) was measured at different laser energies and photoinitiator (PI) concentrations for two concentrations of PEG-dimethacrylate in solution (20% and 30% (w/v)). Hydrogel thickness was a strong function of PEG concentration, PI type and concentration, and energy dosage, and these results were utilized to successfully fabricate complex hydrogel structures using SL, including structures with internal channels of various orientations and multi-material structures. Additionally, human dermal fibroblasts were encapsulated in bioactive PEG photocrosslinked in SL. Cell viability was at least 87% at 2 and 24 h following fabrication. The results presented here indicate that the use of SL and photocrosslinkable biomaterials, such as photocrosslinkable PEG, appears feasible for fabricating complex bioactive scaffolds with living cells for a variety of important tissue engineering applications.

Wetting of bioactive glass surfaces by poly(α-hydroxyacid) melts: interaction between Bioglass® and biodegradable polymers

AbstractThe interfacial characteristics between bioactive glass (45S5 Bioglass®) surfaces and poly(α-hydroxyacid) melts have been assessed by direct wetting measurements. In particular, the wettability of Bioglass® powder by poly(D,Llactide) (PDLLA) and poly(D,L-lactide-co-glycolide) (PLGA) was assessed by imbibition measurements. Additionally, the equilibrium contact angles of PDLLA and PLGA melts on a sintered Bioglass® surface were measured. The surface energy of the bioactive glass and the polymers was determined from contact angles measured using various test liquids on PDLLA, PLGA and Bioglass® solid substrates. There are sufficient adhesive interactions between the polymers and Bioglass®. A simple heat treatment of the bioactive glass in an inert gas atmosphere leads to an improved wetting behaviour, indicating increased adhesive interactions. Scanning electron micrographs of the polymer + Bioglass® composites formed by polymer penetration into the powder bed show the formation of a ‘good quality’ interface.

Characterization of a novel bioactive poly[(lactic acid)‐co‐(glycolic acid)] and collagen hybrid matrix for dermal regeneration

AbstractDifferent strategies have been explored for the purpose of autologous or allogeneic dermal regeneration. We have developed a hybrid matrix by lyophilizing collagen within a poly[(lactic acid)‐co‐(glycolic acid)] (10:90, molar composition) knitted mesh, in order to assimilate the advantages of natural and synthetic materials. The porosity of the mesh was found to be almost 95 %, using Micro‐Computed Tomography Analysis, while the mechanical properties were comparable to native skin. In vitro biocompatibility was analyzed by culturing rat dermal fibroblasts in the matrices over 10 days. The cells were able to attach, proliferate and remain viable within the hybrid matrices. Subsequently, in vivo biocompatibility was analyzed by implanting the matrices subcutaneously in immunocompetent rats, for 2 weeks. Histological analysis showed that the poly[(lactic acid)‐co‐(glycolic acid)]–collagen hybrid matrices evoked minimal host tissue response in vivo. This study forms the basis of using poly[(lactic acid)‐co‐(glycolic acid)]–collagen hybrid matrices for our future work to develop a bioactive matrix for dermal regeneration. Copyright © 2005 Society of Chemical Industry

Evaluations of a Novel Bioactive and Degradable Poly(Ɛ-Caprolactone) Hybrid Material Containing Silanol Group and Calcium Salt as a Bone Substitute

Bioactive poly(e-caprolactone)-siloxane hybrid material was newly developed and its in vitro and in vivo evaluations were made for the potential application as a bone substitute. The polymer precursor, triethoxysilane end capped poly(e-caprolactone) was prepared by the reaction with a,w-hydroxyl poly(e-caprolactone) and 3-isocyanatopropyl triethoxysilane with 1,4-diazabicyclo [2,2,2] octane as a catalyst and toluene as a solvent. The triethoxysilane end capped poly(e-caprolactone) was hydrolyzed and condensed to yield a hybrid sol-gel material. The gelation was carried out for 1 week at ambient condition in a covered Teflon mold with a few pinholes and then dried under vacuum at room temperature for 48 h. Its bioactivity was evaluated by examining the apatite formation on its surface in the SBF and its osteoconductivity was assessed in the tibia of white rabbit. The hybrid material showed apatite-forming ability in the SBF within 1 week soaking. Besides, new bone was formed on the surface of a cylindrical shaped specimen with no histologically demonstrable intervening non-osseous tissue after 6 weeks implantation. There was no evidence of inflammation or foreign body reaction. From the results, it can be concluded that this newly developed hybrid material has osteoconductivity and is likely to be used for the application as a bone graft substitute.

Biological activities of osteoblasts on poly(methyl methacrylate)/silica hybrid containing calcium salt

The biological activity of osteoblasts on the newly developed bioactive poly(methyl methacrylate) (PMMA)/silica hybrid containing calcium salt was investigated. The attachment, proliferation, and differentiation of primary cultured mouse calvarial osteoblasts were evaluated by hexosaminase, MTT, and alkaline phosphatase activity assays, respectively. The PMMA/silica hybrid showed higher biological activities than those of pure PMMA with regard to all three parameters. Besides, the calcium phosphate layer, determined by scanning electron microscopy with energy dispersive spectroscopy, occurred only on the PMMA/silica hybrid. Better biological activities on the PMMA/silica hybrid than those on the PMMA were explained by the role of calcium phosphate layer formed on the PMMA/silica hybrid and the released calcium and silicon ions from it during the cell culture. These results suggest that the PMMA/silica hybrid might be useful as a bone substitute or filler.

Synthesis of a Bioactive Poly(Methyl Methacrylate)/Silica Hybird

Synthesis of a Bioactive Poly(Methyl Methacrylate)/Silica Hybird

Bioactive functionalized polymer of malic acid for bone repair and muscle regeneration

A bioactive poly(β-hydroxyalkanoate) derived from malic acid was prepared and tested on bone repair and muscle regeneration. This functionalized and hydrolyzable polymer was obtained after several steps, the first one being the anionic copolymerization of three malolactonic acid esters. Chemical modifications were carried out on the terpolymer to turn benzyl-protecting groups into carboxyl groups and allyl groups into sulfonate groups. The resulting polymer bore carboxylate, sulfonate, and sec-butyl pendent groups in 65/25/10 molar proportions and were aimed at interacting with heparan binding growth factors. This polymer did not present any toxic effect in cell viability of HepG2 cells, over a large range of concentrations (0.01-0.25 mg l-1). Its ability to improve wound healing was tested in vivo and positive results are reported. Furthermore, the bioactivity of this polymer was evaluated using the regeneration model of Extensor digitorum longus (EDL) rat muscle. The study displayed a significant increase in the muscle regeneration and maturation.

Synthesis and characterization of poly[(3,4‐dihydro‐2h‐pyran)‐alt‐(maleic anhydride)] and its derivatives: Biologically active polymers

AbstractThe syntheses of several monomers, bioactive poly[(3, 4‐dihydro‐2H‐pyran)‐alt‐(maleic anhydride)] and its derivatives, which have different substituents (e.g., acetoxy, methoxy, ethoxy, methoxycarbonyl, formyl, acetoxymethyl, and tosyloxymethyl groups) in the 2‐position of the tetrahydropyran ring of the copolymer backbone, are described. The alternating sequences in copolymers of the dihydropyran derivatives and maleic anhydride were obtained from the equimolar and larger ratios of maleic anhydride to dihydropyran derivative at the onset of the copolymerization. The molecular weights of the copolymers were found to be low (Mn = 1000–7500) due to a transfer reaction of the dihydropyran derivatives. Hydrolyses of the anhydride groups in the copolymers without catalyst afforded poly[(dihydropyran)‐alt‐(maleic acid)] and its derivatives, whereas an additional three copolymers having substituents, e.g., hydroxy, hydroxymethyl, and carboxyl groups were obtained by hydrolyses of the pendent groups (acetoxy, acetoxymethyl, and methoxycarbonyl) with the aid of a hydroxide catalyst. Carbamoyl groups on the polymers were obtained from ammonolysis of methoxycarbonyl groups. The polymers having mercaptomethyl or aminomethyl groups were obtained by substitution of hydrogen sulfide or ammonia for tosyloxylmethyl groups.