Polymeric nanoparticles for selective protein recognition by using thiol-ene miniemulsion photopolymerization.

The fabrication of molecularly imprinted nanoparticles (MIP-NPs) specific for myoglobin by using thiol-ene photopolymerization in miniemulsion was described. Allyl derivatives of phenylalanine as a functional monomer was synthesized and copolymerized with acrylic monomers via miniemulsion polymerization to produce NIP-NPs with approximately 74 nm number average particle diameter. FTIR and 1H-NMR analysis confirmed the synthesis of functional monomer. MIP-NPs were prepared in the existence of myoglobin as a template protein. Morphological investigations exhibited that the particle size of the MIP-NPs, increased compared to the corresponding NIPs and the mean particle diameter by number was measured as 141 nm with narrow distribution. NIP-NPs that were polymerized without myoglobin were found to have less affinity to the target protein. In addition, the rebinding ability of MIP-NPs was much bigger than that of the corresponding NIPs. ELISA results showed that MIPs interact particularly with the myoglobin and show little affinity for BSA in competitive binding experiments.HighlightsAllyl N,N-diallyl phenylalaninate was synthesized as a functional monomer.Imprinted nanoparticles were prepared by using thiol-ene photopolymerization in miniemulsion.The nanoparticles were 141 nm with narrow size distribution.The imprinted nanoparticles showed selectivity toward myoglobin.

Chitosan-co-Hyaluronic acid porous cryogels and their application in tissue engineering.

In this work, the usability of chitosan-co-hyaluronic acid cryogels as a tissue-engineering scaffold was investigated. Chitosan-co-hyaluronic acid cryogels were synthesized at subzero temperature. Cryogels which were composed of various compositions of chitosan and hyaluronic acid (0, 10, 20, 30 and 50wt% hyaluronic acid) was prepared. Morphological studies showed that the macroporous cryogels have been developed with 90-95% porosity. Particularly, the mechanical and biomaterial property of pure chitosan was improved by making copolymer with hyaluronic acid in different concentration. The MTT cell viability results demonstrated that the cryogels have no significant cytotoxicity effect on 3T3 fibroblast and SAOS-2 cells.

[Analysis of degradation failure of poly L-lactic acid fixators used in meniscus tears]. / Menisküs yirtiklarinin atroskopik tamirinde kullanilan poli L-laktik asit sabitleyicilerin erimeme nedenlerinin arastirilmasi.

OBJECTIVES: Biodegradable poly L-lactic acid (PLLA) fixators used in the repair of meniscal tears may cause adverse reactions inside the knee due to delayed degradation. This study was designed to determine the reasons for late degradation of PLLA fixators. METHODS: Three unused and three used meniscal PLLA fixators (BioStinger) were analyzed. The latter were removed from three patients due to persisting symptoms within six months after knee arthroscopy. Fourier transform infrared (FTIR) spectroscopy was performed and external and internal surfaces of the samples were examined by scanning electron microscopy (SEM) and X-ray fluoroscopy (XRF). Chemical structural analyses of two samples (one from each group) were made by 1H-nuclear magnetic resonance (1H-NMR) spectroscopy. Degradation times of two samples (one from each group) by oxidative hydrolysis in hydrogen peroxide solution were recorded. RESULTS: Chemical structure of used and unused fixators did not differ in FTIR analysis. With increasing temperatures, unused and used fixators showed degradation with and without melt flow, respectively. In SEM analysis, inner sections of unused fixators were homogeneous, whereas those of the used ones exhibited crystals which were found to be sodium and potassium chloride salts in XRF analysis. The 1H-NMR spectrum of used and unused samples showed the normal pattern of lactic acid polymer. The unused and used fixators degraded in hydrogen peroxide solution in 10 days and 30 days, respectively. CONCLUSION: Both fixators had the same chemical structure in FTIR and NMR analyses. Formation of salt crystals seemed to be the most important cause of degradation failure, while changes in the physical properties of fixators were thought to be associated with delayed degradation.