Bone tissue engineering seeks to adequately restore functions related to physical and biological properties, aiming at a repair process similar to natural bone. The use of compatible biopolymers, such as bacterial cellulose (BC), as well as having interesting mechanical characteristics, presents a slow in vivo degradation rate, and the ability to be chemically modified. To promote better bioactivity towards BC, we synthesized an innovative BC membrane associated to hydroxyapatite (HA) and anti-bone morphogenetic protein antibody (anti-BMP-2) (BC-HA-anti-BMP-2). We present the physical-chemical, biological and toxicological characterization of BC-HA-anti-BMP-2. Presence of BC and HA components in the membranes was confirmed by SEM-EDS and FTIR assays. No toxic potential was found in MC3T3-E1 cells by cytotoxicity assays (XTT Assay and Clonogenic Survival), genotoxicity (Comet Assay) and mutagenicity (Cytokinesis-blocked micronucleus Test). The in vitro release kinetics of anti-BMP-2 antibodies detected gradually reducing antibody levels, reducing approximately 70% in 7 days and 90% in 14 days. BC-HA-anti-BMP-2 increased SPP1, BGLAP, VEGF, ALPL, RUNX2 and TNFRSF11B expression, genes involved in bone repair and also increased mineralization nodules and phosphatase alcalin (ALP) activity levels. In conclusion, we developed BC-HA-anti-BMP-2 as an innovative and promising biomaterial with interesting physical-chemical and biological properties which may be a good alternative to treatment with commercial BMP-2 protein.
1 October 2003 in Journal of Pharmaceutical Sciences
Biopolymer hosts can be successfully used for the fabrication of multifunctional photonic devices due to their good optical properties, biocompatibility, remarkable mechanical properties and a wealth of chemical functionalization. Particularly, the silk fibroin (SF) biopolymer presents a wide range of suitable properties for photonic applications that were not fully exploited. In the present work, we demonstrate the operation of a distributed feedback (DFB) laser based on SF films doped with Rhodamine 6G (Rh6G) dye and films containing Rh6G and silica or silver nanoparticles. The SF grating structures were fabricated using a commercial blank digital versatile disc (DVD) as the template. The addition of silica or silver nanoparticles to the SF film led to enhanced emission due to the multiple scattering of light by the silica nanoparticles and a reduction of the emission linewidth. The laser wavelength was centered between ≈560 and ≈575 nm corresponding to the fourth-order diffraction of a 750 nm period of the SF grating. The results show that regenerated SF films are promising matrices for DFB lasers because of the excellent optical quality and large potential for biomedicine regarding biocompatibility and benign processing conditions.