In vivo performance of antibiotic embedded electrospun PCL membranes for prevention of abdominal adhesions

The aim of this study was to prepare nonwoven materials from poly(-caprolactone) (PCL) and their antibiotic containing forms by electrospinning, so as to prevent postsurgery induced abdominal adhesions in rats. -Caprolactone was first polymerized by ring-opening polymerization, and then it was processed into matrices composed of nanofibers by electrospinning. A model antibiotic (Biteral®) was embedded within a group of PCL membranes. In the rat model, defects on the abdominal walls in the peritoneum were made to induce adhesion. The plain or antibiotic embedded PCL membranes were implanted on the right side of the abdominal wall. No membrane implantation was made on the left side of the abdominal wall that served as control. Macroscopical and histological evaluations showed that using these barriers reduces the extent, type, and tenacity of adhesion. The antibiotic embedded membranes significantly eliminated postsurgery abdominal adhesions, and also improved healing

In vitro and in vivo degradation of non-woven materials made of poly(e-caprolactone) nanofibers prepared by electrospinning at different conditions

The aim of this study was to prepare non-woven materials from a biodegradable polymer, poly(ε-caprolactone) (PCL) by electrospinning. PCL was synthesized by ring-opening polymerization of ε-caprolactone in bulk using stannous octoate as the catalyst under nitrogen atmosphere. PCL was then processed into non-woven matrices composed of nanofibers by electrospinning of the polymer from its solution using a high voltage power supply. The effects of PCL concentration, composition of the solvent (a mixture of chloroform and DMF with different DMF content), applied voltage and tip–collector distance on fiber diameter and morphology were investigated. The diameter of fibers increased with the increase in the polymer concentration and decrease in the DMF content significantly. Applied voltage and tip–collector distance were found critical to control 'bead' formation. Elongation-at-break, ultimate strength and Young's modulus were obtained from the mechanical tests, which were all increased by increasing fiber diameter. The fiber diameter significantly influenced both in vitro degradation (performed in Ringer solution) and in vivo biodegradation (conducted in rats) rates. In vivo degradation was found to be faster than in vitro. Electrospun membranes were more hydrophobic than PCL solvent-casted ones; therefore, their degradation was a much slower process

Green synthesized silver nanoparticles loaded PVA/Starch cryogel scaffolds with antibacterial properties

In this study, Polyvinyl alcohol/Starch (PVA/Starch) cryogel scaffolds were combined with antibacterial silver nanoparticles (AgNPs), and the antimicrobial properties of composite scaffolds were determined for potential in tissue engineering applications. The porous PVA/Starch scaffolds were prepared by cryogelation technique. The nanoparticles were prepared by green synthesis from Aloe barbadensis leaf extract and characterized. The antibacterial, antifungal and antiyeast properties of AgNPs and AgNPs loaded PVA/Starch cryogel scaffolds were investigated. The highest antimicrobial activity of composite scaffold was found against Pseudomonas aeruginosa. Based on our studies, the results indicate that biodegradable, biocompatible and antimicrobial AgNPs loaded PVA/Starch scaffolds have potential to be used at an infection site in tissue engineering applications

In vivo performance of simvastatin-loaded electrospun spiral-wound polycaprolactone scaffolds in reconstruction of cranial bone defects in the rat model

Cartmell, Sarah/0000-0001-6864-0846; Bolgen, Nimet/0000-0003-3162-0803; Bolgen, Nimet/0000-0003-3162-0803; Meydanli, E. Elif Guzel/0000-0001-9072-3322; KORKUSUZ, PETEK/0000-0002-7553-3915WOS: 000268940100019PubMed: 18671271Reconstruction of large bone defects is still a major problem. Tissue-engineering approaches have become a focus in regeneration of bone. In particular, critical-sized defects do not ossify spontaneously. The use of electrospinning is attracting increasing attention in the preparation of tissue-engineering scaffolds. Recently, acellular scaffolds carrying bioactive agents have been used as scaffolds in "in situ" tissue engineering for soft and hard tissue repair. Poly(epsilon-caprolactone) (PCL) with two different molecular weights were synthesized, and the blends of these two were electrospun into nonwoven membranes composed of nanofibers/micropores. To stimulate bone formation, an active drug, "simvastatin" was loaded either after the membranes were formed or during electrospinning. The matrices were then spiral-wound to produce scaffolds with 3D-structures having both macro- and microchannels. Eight-millimeter diameter critical size cranial defects were created in rats. Scaffolds with or without simvastatin were then implanted into these defects. Samples from the implant sites were removed after 1, 3, and 6 months postimplantation. Bone regeneration and tissue response were followed by X-ray microcomputed tomography and histological analysis. These in vivo results exhibited osseous tissue integration within the implant and mineralized bone restoration of the calvarium. Both microCT and histological data clearly demonstrated that the more successful results were observed with the "simvastatin-containing PCL scaffolds," in which simvastatin was incorporated into the PCL scaffolds during electrospinning. For these samples, bone mineralization was quite significant when compared with the other groups. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 90A: 1137-1151, 2009Turkish Scientific and Technological CouncilTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [105T509]; Turkish Academy of Sciences (TUBA)Turkish Academy of Sciences; BiyomedtekHacettepe UniversityContract grant sponsor: Turkish Scientific and Technological Council (Turkish Scientific and Technological Research Council, TUBITAK, Project: Tissuebiomed); contract grant number: 105T509; Contract grant sponsor: Turkish Academy of Sciences (TUBA); Contract grant sponsor: Biyomedte

Thermoresponsive biodegradable HEMA-lactate-Dextran-co-NIPA cryogels for controlled release of simvastatin

NIPA and HEMA-lactate-Dextran-based biodegradable and thermoresponsive cryogels were synthesized at different compositions by cryogelation. Chemical and morphological properties of the HEMA-lactate-Dextran-co-NIPA cryogel matrices were demonstrated by FTIR, SEM, and ESEM. Thermoresponsivity of the prepared cryogels was investigated by DSC, imaging NMR, and swelling studies. For possible use of the cryogels in potential bone tissue engineering applications, either hydrophobic simvastatin was embedded, or hydrophilic simvastatin was incorporated in the cryogels. Release profiles of simvastatin delivering cryogel scaffolds depending on their composition, hydrophobicity or hydrophilicity of loaded simvastatin and the medium temperature were demonstrated.Peer Reviewe