In Vivo Degradation Studies of PGA-PLA Block Copolymer and Their Histochemical Analysis for Spinal-Fixing Application.

Polylactic acid (PLA) and polyglycolic acid (PGA) are well-known medical-implant materials. Under the consideration of the limitations of degradable polymeric materials, such as weak mechanical strength and by-product release through the biodegradation process under in vivo environments, PLA-PGA block copolymer is one of the effective alternative implant materials in the clinical field. In our previous study, two types of extremely effective PGA-PLA copolymers (multi/tri-block PGA-PLA copolymers) were synthesized.

Advances in the development of hemostatic biomaterials for medical application.

Background: Medical hemostatic biological materials are necessary for the development of the process of preventing and stopping damaged intravascular bleeding. In the process, some red blood cells and white blood cells are trapped in nets. The resulting plug is called a blood clot.

Hemostatic Patches Based on Crosslinked Chitosan Films Applied in Interventional Procedures.

In this study, we manufactured biocompatible hemostatic crosslinked chitosan (CS) patches and analyzed their physicochemical and biological properties for femoral arterial puncture applications. CS is a representative hemostatic material but has some drawbacks, such as swelling, shrinkage, and brittleness. Thus, it was crosslinked via a 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/-hydroxysuccinimide (NHS) coupling reaction and a nucleophilic addition reaction with citric acid (CA), glutaraldehyde (GTA), and genipin (GP) to remedy its shortcomings.

Mechanical Properties and Bioactivity of Polyetheretherketone/Hydroxyapatite/Carbon Fiber Composite Prepared by the Mechanofusion Process.

The main obstacles in the melt-processing of hydroxyapatite (HA) and carbon fiber (CF) reinforced polyetheretherketone (PEEK) composite are the high melting temperature of PEEK, poor dispersion of HA nanofillers, and poor processability due to high filler content. In this study, we prepared PEEK/HA/CF ternary composite using two different non-melt blending methods; suspension blending (SUS) in ethanol and mechanofusion process (MF) in dry condition. We compared the mechanical properties and bioactivity of the composite in a spinal cage application in the orthopedic field.

In Vitro and In Vivo Biosafety Analysis of Resorbable Polyglycolic Acid-Polylactic Acid Block Copolymer Composites for Spinal Fixation.

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA-PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e.

Novel PEEK Copolymer Synthesis and Biosafety - I: Cytotoxicity Evaluation for Clinical Application.

In this research, we synthesized novel polyetheretherketone (PEEK) copolymers and evaluated the biosafety and cytotoxicity of their composites for spinal cage applications in the orthopedic field. The PEEK copolymers and their composites were prepared through a solution polymerization method using diphenyl sulfone as a polymerization solvent. The composite of PEEK copolymer showed good mechanical properties similar to that of natural bone, and also showed good thermal characteristics for the processing of clinical use as spine cage.

In-vitro toxicity study of poly(alkylphenol) as vulcanizing agent.

In this study, cytotoxicity of various novel poly(alkylpehnol) derivatives which, one of constituent for vulcanizing agent, could be adjusted in medical elastic rubber applications were investigated under various conditions of cytotoxicity test. By MTT-assay which according to ISO 10993-5 regulation, we could figure out cell viability of mouse fibroblast in various sample conditions. Furthermore, by Live & Dead Cell assay, we could get colorimetric cell viability via fluorescence images.

Stability study of docetaxel solution (0.9%, saline) using Non-PVC and PVC tubes for intravenous administration.

Background: Di-2-ethylhexyl phthalate (DEHP) are added to poly(vinyl chloride)(PVC) infusion tubes as a plasticizer to ensure tube flexibility. In addition to previously reported disadvantages of DEHP, released DEHP molecules from PVC tubes can easily interact with surfactants in anticancer drug solutions (i.e.

Biodegradable and elastomeric poly(glycerol sebacate) as a coating material for nitinol bare stent.

We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate) (PGS)) using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.

Nanosized polyamidoamine (PAMAM) dendrimer-induced apoptosis mediated by mitochondrial dysfunction.

Nano-materials are currently being used in a variety of fields. One of the concerns associated with their use is their potential to harm human health. In an attempt to identify genes expressed differently in human lung cells (WI-26 VA4) exposed to nanosized (45 nm in diameter) PAMAM (polyamidoamine) dendrimers, we observed down-regulation of mitochondrial DNA-encoded genes involved in the maintenance of mitochondrial membrane potential.

Control over micro-fluidity of liposomal membranes by hybridizing metal nanoparticles.

This study introduces a facile method to hybridize metal nanoparticles with lipid vesicles, which allows us to control over their membrane micro-fluidity. We have fabricated these hybrid liposomes by directly hybridizing metal nanoparticles with lipid bilayers solely consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC). For this, we have used the dehydration and rehydration method.

Quantitative characterization of degradation behaviors of antioxidants stabilized in lipid particles.

This study describes a flexible approach that allows us to characterize the long-term stability of antioxidants by using a thermodynamically extended Arrhenius equation. We use retinol, Vitamin A, as a model antioxidant and its degradation behaviors are characterized for both stabilized and non-stabilized systems; in this study, by using a fluid bed technique, we immobilize the retinol in lipid particles, thus increasing its thermal stability in complex formulations, such as aqueous polymer gels and emulsions. Our approach demonstrates that the degradation behaviors of the retinol show a functional relationship with temperature and time, which makes it possible to use the Arrhenius approach.