Day 2 :
Keynote Forum
T. Aoyagi
Nihon University, Japan
Keynote: Preparation of functionalized PCL-based materials for biomedical application
Time : 10:00-10:30
Biography:
Dr. Takao Aoyagi is Professor of Department of Materials and Applied Chemistry of Nihon University in Tokyo, Japan. He received his Ph.D. at Tokyo Institute of Technology in 1993. After finishied Graduate School of Science and Engineering of Waseda University, he belonged to a Japanese chemical company (Lion Corporation, 1986-1987) and private institute (Sagami Chemical Research Center, 1987-1995). He became an assistant professor at Institute of Biomedical Engineering in 1995 and associated professor in 2001, Tokyo Women’s Medical University. In 2002, he was promoted to full professor of Department of Nanostructure and Advanced Materials of Kagoshima University. In 2009, he moved to the Biomaterials Center and Coordinating Director of Nanotech-driven Materials Research for Biotechnology, National Institute for Materials Science (NIMS) in Tsukuba, Japan. His present research field is design of smart biomaterials for biomedical applications
Abstract:
So far, aliphatic polyesters, especially, poly(glycolide) (PGA), poly(lactide) (PLA), poly(ï¥-caprolactone) (PCL) and their copolymers have withdrawn much attentions as biodegradable polymeric materials, because of their superior properties, such as mechanical strength, easiness of polymerization and manufacturing, biodegradability, and so on. Among them, there are many PCL-related researches as biodegradable materials have been already used as artificial dura mater clinically. We have reported that surface shape memory materials derived from PCL could contributed to mechano-biological studies using the same materials with modulated elasticity and viscosity by only temperature change. Furthermore, drug permeation control near body temperature could be succeeded by effective melting point modulation. In this study, new PCL network material which has cationic groups is prepared. The cationic moieties would interact to anionic groups easily, for example sialic acid in sugar chains. As other functional materials, we have been studying the methodology to introduce functional materials into the PCL main chains for immobilization of bio-active molecules, So such polymeric materials are expected to interact to living cells or tissues. To achieve such purpose, we newly designed blanched PCL macromonomer which has bromomethyl groups at the all of chain ends. Then, these terminal halomethyl groups reacted to 2, 2’-dimethylaminoethyl methacrylate to afford the objective macromonomer as seen in Figure 1. The corresponding macromonomer solution was cast and UV light was irradiated in the presence of photo-sensitizer. Briefly, 4-blanced PCL were prepared by ring opening polymerization initiated with pentaerythritol. Hydroxy groups at the chain ends reacted bromoacetyl bromide. The reaction with 2,2’-dimethylaminoethyl methacrylate afforded the N-methacryloylethyl, N’, N’’-dimethylammonio- terminated PCL macromonomers. This cationic PCL macromonomer THF solution were poured into the space of two glass plates with the Tefron spacers. To both sides of the glass plates, UV light was irradiated for cross-linking reaction to obtain membrane-type materials. The surface properties of the cationic PCL cross-linked membrane were evaluated by contact angle measurement of water droplet and anionic compound. As expected, the cationic PCL cross-linked membrane showed larger hydrophilicity and the much greater dye adsorption than the naked PCL. These results suggest that such materials would enhance the living cells interaction and be useful for protein immobilization on the surfaces
Keynote Forum
Ana Paula Testa Pezzin
University of Joinville Region (UNIVILLE), Brazil
Keynote: Recent advances in bacterial nanocellulose for different applications
Time : 10:30-11:00
Biography:
Ana Paula Testa Pezzin. Graduated in Chemistry, Master in Chemical Engineering and PhD in Mechanical Engineering from the State University of Campinas. She did postdoctoral studies at the Université Pierre et Marie Curie in Paris / France. She has been a leader in the POLYMERIC MATERIALS GROUP since 2001, working in research lines: Polymeric biomaterials for medical and dental applications; Composites, biocomposites, nanocomposites and bionanocomposites; Modification of biopolymers for different applications and synthesis and characterization of biopolymers by microbial culture. Currently, she is a Professor and Researcher at the University of Joinville Region (UNIVILLE), being a level 2 productivity fellow at CNPq
Abstract:
The last years of advances in research have demonstrated the importance and potential of biopolymers for a variety of applications, particularly for biopolymers produced by microorganisms, including bacterial nanocellulose (BNC). These polymers can be biosynthesized by bacteria of some genera, but the most efficient producers of cellulose belong to the genus Gluconacetobacter, that secrets an abundant 3-D network of cellulose fibrils. There are two main methods for producing BNC: static culture, which results in the accumulation of a thick, leather-like white BNC pellicle at the air-liquid interface, and stirred culture, in which cellulose is synthesized in a dispersed manner in the culture medium, forming irregular pellets. BNC can also be synthesized from a variety of substrates such as glucose, sucrose, fructose, glycerol, mannitol, among others. In this way it is possible to modify and control the physical properties of the cellulose during its biosynthesis. Factors such as yield, morphology, structure, and physical properties may be affected by the method of production and culture medium used. The thickness, color and transparency of the membrane can be controlled by means of the culture time of the bacterium. The BNC appears as a competitive alternative, having as main characteristics: high crystallinity, high tensile strength, elasticity, durability, hydrophilic potential (retention capacity and water absorption - about 98% to 99% of its volume is composed of liquids). In the food industry, it is used in the production of coconut cream, ice cream, snacks, sweets, stabilizers for emulsions and foams. In the cosmetics industry BCN is used as moisturizers and astringents. BNC is also used as an additive of high quality papers, membranes for high quality audio devices, electronic papers (e-papers), diaphragms for eletroacustic transducers, liquid crystal displays, OLED support, ultrafiltration membranes (water purification) and membranes for mineral oil recovery. In the biomedical area BCN is suitable for tissue regeneration, drug delivery systems, vascular grafts, scaffolds for tissue engineering, artificial blood vessels and microvessels, artificial vascular implant, dental implants, artificial skin, dressing for wounds and burns, allowing the transfer of medications to the wound while serving as an effective physical barrier against external infection. In the materials area NCB whiskers can also be used as reinforcement in nanocomposites.
Coffee Break: 11:00-11:20 @ Tiburan/Sausalito Foyer