INTRODUCTION Poly-L-lactic acid (Sculptra, Sanofi Aventis, Bridgewater, NJ) is a gel polymer made of poly-Llactic acid microspheres and water suspended in a mannitol and carboxymethyl cellulose suspension. This injectable tissue filler has been used for correction of lipoatrophy in HIV patients as well as for cosmetic purposes since its US Food and Drug Administration approval in 2004. The mech...

Bones constructed by tissue engineering are being considered as valuable materials to be used for regeneration of large defects in natural bone. In an attempt to prepare a new bone construct, in this study, proliferation and bone differentiation of marrow-derived mesenchymal stem cells (MSCs) on our recently developed composite scaffolds of nano-, micro-hydroxyapatite/ poly(l-lactic acid) were ...

For biodegradable polymers such as poly (Llactic acid) (PLLA), material crystallinity has a considerable effect on degradation and physical properties. In this work, the effects of laser fluence of a 355 nm UV Q-switched Nd-YAG laser on the crystallinity and conformation at the surface of PLLA films and the factors affecting the transformation are investigated. Electron microscopy, X-ray diffra...

LLactic acid bacteria (LAB) are used widely in food microbiology as probiotics and biopreservatives to extend shelf life of items. Lactic produced by LAB strains precursor polylactic acid(PLA) that has growing demand bioplastics biodegradable nature replacing traditional plastics. have the potential utilize polysaccharides from various sources produce lactic acid. The aim this study is identify...

P roponents of bioresorbable scaffolds (BRS) define them as a transformative technology suggesting that coronary repair will improve long-term clinical outcomes. Skeptics have questioned the early safety, and overall merit of BRS in the era of secondand third-generation drug-eluting metallic stents (DES). Nevertheless, BRS have sparked enormous interest and debate. Indeed, over the last decade ...

peripheral nerve injuries caused by traffic accidents, resections of tumors or iatrogenic side effects of the surgeries are few of the most common form of trauma occurring with up to 500,000 cases each year in iran. conventional strategies including nerve coaptation, and the application of autografts, allografts and xenografts are restricted due to the limited availability of donors, immune-rej...

poly urea-formaldehyde was synthesized simply and rapidly from urea and formaldehyde by condensation polymerization and studied for the sorption of trace acid blue from aqueous solution. the optimum ph value for sorption of the acid blue was 4. experimental results showed that the sorption capacity of poly urea-formaldehyde for acid blue was determined. the synthetic polymer can be reused for 5...

thermodynamic study on the interaction of β-cd with poly ethylene oxide and poly acrylic acid was performed by isothermal titration calorimetry at 298k. when β-cd is added to the interpolymer complex, competition is created between host-guest and hydrogen bond. enthalpy of interaction between the β-cd and interpolymer complex was calculated using the extended solvation theory. p=1 shows that wi...

in this research, hydrogels based on poly vinyl alcohol and poly acrylic acid blend were prepared which were cross-linked by applied thermal conditions. afterward, effects of time and heating on water uptake were investigated. the highest water uptake value exhibited by the sample that was heated for 20 min. at 110 ºc was about 2129% after 4 days at equilibrium state. hydrogels exhibited ph-sen...

physical, mechanical and structural properties of poly(lactic acid) (pla)-basedfilms containing different amounts of nanoclay and cellulose prepared bysolvent casting method were examined. physical properties including thickness,transparency and color did not change significantly with addition of nanoparticles to the polymer matrix. x-ray diffraction (xrd) patterns showed that pure pla has a se...