Development of Biocompatible Electrospun PHBV-PLLA Polymeric Bilayer Composite Membranes for Skin Tissue Engineering Applications.

Bilayer electrospun fibers aimed to be used for skin tissue engineering applications were fabricated for enhanced cell attachment and proliferation. Different ratios of PHBV-PLLA (70:30, 80:20, and 90:10 w/w) blends were electrospun on previously formed electrospun PHBV membranes to produce their bilayers. The fabricated electrospun membranes were characterized with FTIR, which conformed to the characteristic peaks assigned for both PHBV and PLLA. The surface morphology was evaluated using SEM analysis that showed random fibers with porous morphology. The fiber diameter and pore size were measured in the range of 0.7 ± 0.1 µm and 1.9 ± 0.2 µm, respectively. The tensile properties of the bilayers were determined using an electrodynamic testing system. Bilayers had higher elongation at break (44.45%) compared to the monolayers (28.41%) and improved ultimate tensile strength (7.940 MPa) compared to the PHBV monolayer (2.450 MPa). In vitro cytotoxicity of each of the scaffolds was determined via culturing MC3T3 (pre-osteoblastic cell line) on the membranes. Proliferation was evaluated using the Alamar Blue assay on days 3, 7, and 14, respectively. SEM images of cells cultured on membranes were taken in addition to bright field imaging to visually show cell attachment. Fluorescent nuclear staining performed with DAPI was imaged with an inverted fluorescent microscope. The fabricated bilayer shows high mechanical strength as well as biocompatibility with good cell proliferation and cell attachment, showing potential for skin substitute applications.

Silk Meshes Coated with Chitosan-Bioactive Phytochemicals Activate Wound Healing Genes In Vitro.

Meshes from natural silk are hand knitted and surface functionalized to facilitate hernia repair and other load bearing, tissue applications. Purified organic silk is - hand knitted and then coated with chitosan (CH)/bacterial cellulose (BC) blend polymer using four phytochemicals such as pomegranate (PG) peel, Nigella sativa (NS) seed, Licorice root (LE), and Bearberry leaf extracts (BE) separately. Characterizations using GCMS analysis shows the presence of bioactive chemicals in the extracts. Scanning electron microcopy (SEM) shows that the surface is coated with the composite polymer t. Fourier transform infrared spectroscopy (FTIR) shows significant elements found in CH, BC, and phytochemicals in plant extracts with no chemical changes. Tensile strength of the coated meshes is higher to support tissue as implants. The release kinetics suggest sustained release of phytochemical extracts. In vitro studies confirmed the noncytotoxic, biocompatible, wound healing potential of the meshes. Furthermore, gene expression analysis of 3-wound healing genes shows marked increase in the in vitro cell cultures due to the presence of extracts. These results suggest that the composite meshes can efficiently support hernia closure while facilitating wound/tissue healing and combating bacterial infections. Therefore, these meshes can be good candidates for fistula and cleft palate repair.

Comparison of suture and graft techniques in secondary unilateral cleft rhinoplasty.

Every surgeon should master several techniques to modify the nasal tip. For secondary rhinoplasty, various techniques have been described. A modified technique of using the cephalic trim portion of lower lateral cartilage as onlay tip graft is also described. The objective of this single-blind randomized controlled trial was to compare the outcome of suture-only techniques and grafts-plus-suture techniques in terms of postoperative tip projection made measurable by the patient as excellent, good, or poor. Sixty patients with cleft nasal tip deformity who gave informed consent were included and randomly assigned to either technique. Patients requiring osteotomies and previously operated on for cleft rhinoplasty were excluded. Postoperative tip projection was assessed by the patient 6 months postoperatively. Mean age was 28.5 ± 2.1 years in suture technique (group A) and 29.1 ± 1.9 in suture-plus-graft technique (group B). There were 20 males (66.7%) and 10 females (33.3%) in group A and 22 males (73.3%) and 8 females (26.5%) in group B. Nasal deformity was moderate in 66.7% of cases in group A and 60.0% of cases in group B, whereas nasal deformity was severe in 33.3% of cases in group A and 40% of cases in group B. Postoperative tip projection was excellent in 7 patients (23.3%) in group A and 22 patients (73.3%) in group B, and good in 4 patients (13.3%) in group A and 5 patients (16.7%) in group B, whereas poor results were observed in 19 patients (63.4%) in group A and 3 patients (10.0%) in group B (P = 0.001). Graft-plus-suture technique is an effective method for improving the tip projection.

Thyroxine impregnated chitosan-based dressings stimulate angiogenesis and support fast wounds healing in rats: Potential clinical candidates.

This research paper demonstrates efficacy of chitosan and thyroxine loaded chitosan (CS) dressings for their angiogenic and wound healing potential. The dressings were prepared by freeze gelation method. Thyroxine was loaded by physical adsorption into chitosan membranes. The porosity was analyzed by scanning electron microscopy (SEM) and chemical structures were investigated by Fourier transform infra-red spectroscopy (FTIR). Cell culture studies showed materials were non-toxic and chorioallantoic membranes assay (CAM) confirmed that the thyroxine loaded chitosan stimulated angiogenesis much higher than simple chitosan dressings. In addition, thyroxine loaded dressings showed excellent wound healing potential when tested on full thickness rats wounds. A good epithelialization was obtained along with robust wound closure. Overall, as compared to chitosan, thyroxine containing membranes showed high level of angiogenesis and fast wound healing.