This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /SiO2-CaO-P2O5 by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /SiO2-CaO-P2O5 hybrid xerogel potentially could be used as a bone tissue engineering material.
hybrid; xerogel; silk fibroin; SiO2-CaO-P2O5; bone tissue engineering
Xiaohong Wu: School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road,Fuzhou 350002, China
Fuhua Yan: Institute and Hospital of Stomatology, Nanjing University Medical School, 30 Zhongyang Road, Nanjing, Jiangsu, 210008, China.
Wei Liu and Hongbing Zhan: College of Materials Science and Engineering, Fuzhou University, 2 Xueyuan Road, Fuzhou 350108, China
Wenrong Yang: School of Life and Environmental Science, Waurn Ponds Campus, Geelong Deakin University, Australia
Covalent attachment of 1, 4-dimethylnaphthalene (DMN) based endoperoxide forming subunits to a polyvinyl butyral (PVB) backbone has been achieved. The functionalized polymer materials prepared and characterized here can serve as biocompatible carrier systems for studying cellular uptake, intermediate storage and delayed release of singlet oxygen, which opens up new doors for optimizing a variety of medical applications of photogenerated DMN-endoperoxides such as antiviral, antibacterial, antiplasmodial and antitumor activity.
dimethyl naphthalene; Polyvinyl butyral; endoperoxides; singlet oxygen; drug carriers
Damir Posavec and Gunther Knor: Institute of Inorganic Chemistry, Johannes Kepler University Linz (JKU), Altenbergerstrasse 69, A-4040 Linz, Austria
Rainer Muller and Udo Bogner: Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040 Regensburg, Germany
Gunther Bernhardt: Institute of Pharmacy, University of Regensburg, 93040 Regensburg, Germany
An in vitro cell study evaluating cell adhesion to hydroxyapatite (HA) coated prosthetic Ti-6Al-
4V alloy via laser treatment is presented in comparison with uncoated alloy. Based on our previous in vitro biocompatibility study, which demonstrated higher cell attachment and proliferation with MC3T3 preosteoblast cells, the present investigation aims to reveal the effect of laser coating Ti alloy with HA on the adhesion strength of bone-forming cells against centrifugal forces. Remaining cells on different substrates after centrifugation were visualized using fluorescent staining. Semi-quantifications on the numbers of cells
were conducted based on fluorescent images, which demonstrated higher numbers of cells retained on HA laser treated substrates post centrifugation. The results indicate potential increase in the normalized maximum force required to displace cells from HA coated surfaces versus uncoated control surface. The possible mechanisms that govern the enhancing effect were discussed, including surface roughness,
chemistry, wettability, and protein adsorption. The improvement in cell adhesion through laser treatment with a biomimetic coating could be useful in reducing tissue damage at the prosthetic to bone junction and minimizing the loosening of prosthetics over time.
Laser coating; hydroxyapatite; centrifugation; adhesion; osteoblast
Lu Huang, Yu Cao and Wei He: Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996-2100, USA
Samuel C. Goddard and Wei He: Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN 37996-2210, USA
Santhanakrishnan Soundarapandian, Narendra B. Dahotre: Laboratory for Laser Aided Additive and Subtractive Manufacturing, Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203-5017, USA
The objective of this study was to evaluate the cytotoxicity of poly (lactic acid) (PLA) nanoparticles. We used a water-soluble, amphiphilic phospholipid polymer, poly (2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB30W), as a stabilizer for the PLA nanoparticles. The PLA nanoparticles and PMB30W-modified PLA (PLA/PMB30W) nanoparticles were prepared by evaporating tetrahydrofuran (THF) from its aqueous solution. Precipitation of the polymers from the aqueous solution produced PLA and PLA/PMB30W nanoparticles with a size distribution of 0.4-0.5
optimal stiffness; beam vibrations; transfer functions; optimal support location; support stiffness
Hyung Il Kim and Kazuhiko Ishihara: Department of Bioengineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Synthesis of interpenetrating polymer network (IPN) of chitosan-gelatin (Cs-Ge) (as a primary network) and N-isopropylacrylamide (NIPAAm) monomer (as the secondary network) was carried out with different ratio. Its structure was characterized by FT-IR, which indicated that the IPN was formed. The memberanes were studied by swelling, weight loss with time. The interior morphology of the IPN hydrogels was revealed by scanning electron microscopy (SEM); the IPN hydrogels showed a interpenetrated network of NIPAAm/chitosan has layers with more minute stoma and canals compared to interpenetrated network of NIPAAm/gelatin. Lower critical solution temperature (LCST), equilibrium swelling ratio (ESR) and de-swelling kinetics were measured. The DSC results noticed that LCST of IPN hydrogels with different ratio of Cs/Ge/PNIPAAm are around 33
gelatin; chitosan; N-isopropylacrylamide; thermosensitive hydrogel
Shaghayegh Baghaei: Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Mohammad T. Khorasani: Biomaterial Department of Iran Polymer and Petrochemical Institute, P.O. BOX 14965/115, Tehran, Iran