Katarzyna Jaszcz

Synthesis of functional polycarbonates by copolymerization of carbon dioxide with allyl glycidyl ether

Functional aliphatic polycarbonate was synthesized by copolymerization of carbon dioxide and allyl glycidyl ether in the presence of a catalyst system based on ZnEt 2 and pyrogallol at a molar ratio of 2:1. The polycarbonate obtained was oxidized with m-chloroperbenzoic acid to give poly(epoxycarbonate). These polymers were degraded in an aqueous buffer of pH 7.4 at 37°C. Hydrolytic degradation was monitored by determination of the weight loss.

Synthesis and Modification of Functional Polycarbonates with Pendant Allyl Groups

Functional aliphatic polycarbonates with pendant allyl groups were synthesised by copolymerization of carbon dioxide and allyl glycidyl ether (AGE) in the presence of a catalyst system based on ZnEt2 and pyrogallol at a molar ratio 2 : 1. The functionality of some polycarbonates was reduced by replacing a part of allyl ether with saturated glycidyl ether, i.e., butyl glycidyl ether (BGE) or isopropyl glycidyl ether (IGE). Polycarbonates obtained by the copolymerization of AGE and CO2 or by the terpolymerization of AGE, IGE and CO2 were oxidized with m-chloroperbenzoic acid to their respective poly(epoxycarbonate)s. The influence of the AGE/ΣGE ratio in the polycarbonates, the polymer concentration in the reaction solution and the duration of the reaction on the conversion of allyl groups into glycidyl ones was examined. A tendency to gelation of the initial and oxidized polycarbonates during storage was observed. The initial polycarbonates and their oxidized forms were degraded in aqueous buffer of pH = 7.4 at 37°C. The course of hydrolytic degradation was monitored by the determination of mass loss.

Studies on copolymerization of succinic anhydride and allyl glycidyl ether

Functional aliphatic polyesters were synthesised by melt copolymerization of succinic anhydride (SA) and allyl glycidyl ether (AGE) in the presence of benzyltrimethylammonium chloride (BTMAC) as a catalyst. The influence of the parameters of the process: AGE/SA feed ratio, duration of the reaction, amount of water and of the catalyst added on the reaction course and on characteristics of the products obtained has been examined. Tendency to gelation of the polyesters during some syntheses and increase of molecular weight after consumption of functional groups were observed.

Novel bioactive polyester scaffolds prepared from unsaturated resins based on isosorbide and succinic acid.

In this study new biodegradable materials obtained by crosslinking poly(3-allyloxy-1,2-propylene succinate) (PSAGE) with oligo(isosorbide maleate) (OMIS) and small amount of methyl methacrylate were investigated. The porous scaffolds were obtained in the presence of a foaming system consisted of calcium carbonate/carboxylic acid mixture, creating in situ porous structure during crosslinking of liquid formulations. The maximum crosslinking temperature and setting time, the cured porous materials morphology as well as the effect of their porosity on mechanical properties and hydrolytic degradation process were evaluated. It was found that the kind of carboxylic acid used in the foaming system influenced compressive strength and compressive modulus of porous scaffolds. The MTS cytotoxicity assay was carried out for OMIS using hFOB1.19 cell line. OMIS resin was found to be non-toxic in wide range of concentrations. On the ground of scanning electron microscopy (SEM) observations and energy X-ray dispersive analysis (EDX) it was found that hydroxyapatite (HA) formation at the scaffolds surfaces within short period of soaking in phosphate buffer solution occurs. After 3h immersion a compact layer of HA was observed at the surface of the samples. The obtained results suggest potential applicability of resulted new porous crosslinked polymeric materials as temporary bone void fillers.

Effect of Basic Factors of Preparation on Characteristics, Hydrolytic Degradation, and Drug Release From Poly(ester-anhydride) Microspheres

Functional poly(ester-anhydride) microspheres were prepared using emulsion solvent evaporation (ESE) and phase inversion methods (PIM). The poly(ester-anhydride)s were obtained by polycondensation of sebacic acid (SBA) and oligo(3-allyloxy-1,2-propylene succinate) terminated with carboxyl groups (OSAGE). The effects of various parameters, including: polymer and emulsifier concentrations, stirring speed and molecular weight of polyvinyl alcohol (PVA) used as emulsifier on size, size distribution and morphology of microspheres obtained by ESE technique were examined. The size of microspheres obtained was in the range 2–30 µm and depended mainly on the stirring rate in emulsion formulation process, as well as concentration of polymer solution used. Molecular weight of PVA, and its concentration in aqueous phase, significantly influenced tendency to agglomeration of microparticles formed, but only slightly changed the size of microspheres. The present study demonstrated that the ESE method can be useful to formulate, from functional poly(ester-anhydride)s, small (2–3 µm) or large (20–30 µm) microspheres with relatively narrow size distribution. Such microspheres were loaded with three model compounds (rhodamine B, p-nitroaniline, and piroxicam) with different water solubility and their release characteristics were examined. In the present study microparticles were also obtained by alternative phase inversion method to compare mainly stability of polymers during formulation of microspheres by both techniques.

Preliminary studies on the hydrolytic degradation and biocompatibility of poly(3-allyloxy-1,2-propylene succinate).

In the present paper the synthesis and selected properties of functional aliphatic poly(3-allyloxy-1,2-propylene succinate) (PSAGE) are described. This polyester was synthesized by melt co-polymerization of succinic anhydride and allyl glycidyl ether in the presence of benzyltrimethylammonium chloride as catalyst. The chain structure of PSAGE and its end-groups was characterized by MALDI-TOF mass spectrometry. It was found that PSAGE undergoes hydrolytic degradation in phosphate buffer solution (pH 7.41) at 37°C and, unexpectedly, the dependence of mass loss on immersion time turned out to be linear in the first 12 weeks, similar to hydrophobic polyanhydrides. The polysuccinate of 3600 Da was tested on rat alveolar macrophage cell line using the MTT assay to determine its cytotoxicity, as well as the NO production level, which is an indicator of cell activation. The data obtained show that PSAGE is non-toxic, and that the viability of cells ranges from 86 to 100%. The obtained results reveal the potential applicability of PSAGE as a component of biomaterials or as polymeric drug carrier.

Characterization of new biodegradable bone cement compositions based on functional polysuccinates and methacrylic anhydride

New biodegradable poly(3-allyloxy-1,2-propylene)succinate-based materials were obtained by cross-linking poly(3-allyloxy-1,2-propylene)succinate (PSAGE) with methyl methacrylate (MMA) and methacrylic anhydride (MAAH). The aim of this study was to examine the influence of MAAH/MMA ratio and incorporation of biphasic calcium phosphate (BCP) filler on the maximum curing temperature, setting time, compressive strength and modulus of the cured materials, as well as on their hydrolytic degradation. The latter was characterized by determination of the weight loss and observation of changes in samples morphology by SEM. The maximum temperature during cross-linking was found to decrease with increasing MAAH content. The setting time was affected strongly by the concentration of double bonds and was rapidly shortened with its increase. The compressive strength and compressive modulus values increased with increasing MAAH/MMA ratio. Moreover, addition of bioactive mineral filler (BCP) improves significantly mechanical properties of these materials. On the other hand, it slows down their hydrolytic degradation.

Synthesis and Characteristics of Biodegradable Epoxy-Polyester Resins Cured with Glutaric Anhydride

Biodegradable epoxy-polyester resins were synthesized in two steps: (1) the synthesis of the polyesters with allyl pendant groups, and (2) the epoxidation of the allyl groups in the polyesters. Polyesters with allyl pendant groups were synthesized by the melt copolymerization of succinic anhydride (SA) and allyl glycidyl ether (AGE) in the presence of benzyltrimethylammonium chloride (BTMAC) as the catalyst. The functionality of some polyesters was reduced by replacing a part of AGE with butyl glycidyl ether (BGE). The epoxidation of the polyesters obtained was carried out using m-chloroperben- zoic acid (MCPBA). The multifunctional epoxy-polyester resins were cured with different amounts of glutaric anhydride (GA). The course of the curing process was monitored using DSC method. The following parameters of the process were determined: heat of curing, onset, maximal and end temperatures. Glass transition temperatures (T g s) of the cured resins were determined by dynamic mechanical thermal analysis (DMTA). The influence of the composition of the initial resins and amount of GA on the properties of the cured products, such as density, hardness, T g values, swelling and water sorption, were examined. Epoxy-polyester resins were subjected to the test of accelerated hydrolytic degradation in an aqueous phosphate buffer of pH = 7.4 at 70 °C.

Highly porous crosslinked poly(ester-anhydride) microspheres with high loading efficiency

Microparticles with diameter within the range of Dn = 26–38 μm were prepared from functional poly(esteranhydride)s with different amount of allyl groups in the side chains, using emulsion solvent evaporation technique. Porous structure was obtained as the effect of photocrosslinking of allyl groups. 2,2-Dimetoxy-2-phenylacetophenone (DMPA) (0.5 wt%–10 wt%) was used as a photoinitiator. The crosslinking was carried out by UV irradiation during the solvent evaporation. Effectiveness of the crosslinking was characterized by the content of insoluble part of samples and it was in the range of 18%–75%. Porosity of microparticles (in the range of 76%–88%) depended on the functionality of poly(esteranhydride) s and amount of the photoinitiator used. The most porous particles were obtained with use of 0.5 wt% of DMPA. Their flow ability expressed by Carr’s index was excellent, and their theoretical mass mean aerodynamic diameters were acceptable for use in pulmonary drug delivery. The most porous particles were loaded with p-nitroaniline, theophilline or doxycycline. The loading efficiencies of drugs in porous microspheres were higher compared to nonporous ones. The porosity of loaded microparticles was slightly decreased, however their flow ability was still very good.

Preliminary Studies on the Properties of Novel Polymeric Composite Materials Based on Polysuccinates

This study aimed to prepare novel biodegradable polymeric composites based on poly(3-allyloxy-1,2-propylene) succinate (PSAGE). These composite materials are composed of poly(ester-anhydride) (PEA) microspheres embedded in polyester matrix prepared by crosslinking PSAGE with oligo(1,2-propylene maleate) and methacrylic monomers. Methyl methacrylate and one of hydrophilic oligo(ethylene glycol) dimethacrytes with different length of oligooxyethylene chains were used as polymerizable solvents. Incorporation of microspheres that degrade faster than crosslinked polyester matrices enables formation of porous structure. The obtained materials are liquid before curing and harden in several minutes with moderate exothermic effect. The effect of the composition of polyester matrices and kind of PEA microspheres used on selected properties, such as water sorption, mechanical strength, porosity, and hydrolytic degradation behavior, was investigated. The morphology of the cured composite materials subjected to hydrolytic degradation was evaluated by SEM.