Plant Fibers as Composite Reinforcements for Biomedical Applications.

Plant fibers possess high strength, high fracture toughness and elasticity, and have proven useful because of their diversity, versatility, renewability, and sustainability. For biomedical applications, these natural fibers have been used as reinforcement for biocomposites to infer these hybrid biomaterials mechanical characteristics, such as stiffness, strength, and durability. The reinforced hybrid composites have been tested in structural and semi-structural biodevices for potential applications in orthopedics, prosthesis, tissue engineering, and wound dressings.

Antimicrobial Properties of Plant Fibers.

Healthcare-associated infections (HAI), or nosocomial infections, are a global health and economic problem in developed and developing countries, particularly for immunocompromised patients in their intensive care units (ICUs) and surgical site hospital areas. Recurrent pathogens in HAIs prevail over antibiotic-resistant bacteria, such as methicillin-resistant (MRSA) and . For this reason, natural antibacterial mechanisms are a viable alternative for HAI treatment.

Synthesis and Evaluation of AlgNa-g-Poly(QCL-co-HEMA) Hydrogels as Platform for Chondrocyte Proliferation and Controlled Release of Betamethasone.

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components.

Use of Human Umbilical Cord and Its Byproducts in Tissue Regeneration.

The fresh or cryopreserved human umbilical cord (HUC) and its byproducts, such as cells and extracts, have different uses in tissue regeneration. Defining what HUC byproduct is more effective in a particular application is a challenge. Furthermore, the methods of isolation, culture and preservation, may affect cell viability and regenerative properties.

A novel photocrosslinkable and cytocompatible chitosan coating for Ti6Al4V surfaces.

Background: In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most widely used alloy in orthopedic implants, so as to improve the biological tissue response at the metallic surface.

Methods: The Ti6Al4V surface was sandblasted with alumina particles. CH was chemically modified, via carbodiimide chemistry, using lactobionic and 4-azidebenzoic acid to make it soluble at physiological pH and photocrosslinkable, respectively.

Enhanced osteoblastic differentiation of mesenchymal stem cells seeded in RGD-functionalized PLLA scaffolds and cultured in a flow perfusion bioreactor.

The present study combines chemical and mechanical stimuli to modulate the osteogenic differentiation of mesenchymal stem cells (MSCs). Arg-Gly-Asp (RGD) peptides incorporated into biomaterials have been shown to upregulate MSC osteoblastic differentiation. However, these effects have been assessed under static culture conditions, while it has been reported that flow perfusion also has an enhancing effect on MSC osteoblastic differentiation.

Preparation of a functionally flexible, three-dimensional, biomimetic poly(L-lactic acid) scaffold with improved cell adhesion.

Poly(L-lactic acid) (PLLA) is widely used in tissue-engineering applications because of its degradation characteristics and mechanical properties, but it possesses an inert nature, affecting cell-matrix interactions. It is desirable to modify the surface of PLLA to create biomimetic scaffolds that will enhance tissue regeneration. We prepared a functionally flexible, biomimetic scaffold by derivatizing the surface of PLLA foams into primary amines, activated pyridylthiols, or sulfhydryl groups, allowing a wide variety of modifications.

Improved mesenchymal stem cell seeding on RGD-modified poly(L-lactic acid) scaffolds using flow perfusion.

Arg-Gly-Asp (RGD) has been widely utilized to increase cell adhesion to three-dimensional scaffolds for tissue engineering. However, cell seeding on these scaffolds has only been carried out statically, which yields low cell seeding efficiencies. We have characterized, for the first time, the seeding of rat mesenchymal stem cells on RGD-modified poly(L-lactic acid) (PLLA) foams using oscillatory flow perfusion.

Pre-culture period of mesenchymal stem cells in osteogenic media influences their in vivo bone forming potential.

The objective of this study was to investigate if the in vitro pre-culture period in osteogenic media of rat mesenchymal stem cells (MSCs), influences their ability to regenerate bone when implanted in a critical size cranial defect. MSCs were harvested from the bone marrow of 6-8 weeks old male Fisher rats and expanded in vitro in osteogenic media for different time periods (4, 10, and 16 days) in tissue culture plates (TCP), seeded on sintered titanium fiber meshes without the extracellular matrix (ECM) generated in vitro, and implanted in the rat cranium after 12 h. Thirty two adult Fisher rats received the implants, divided in four groups.

Flow perfusion improves seeding of tissue engineering scaffolds with different architectures.

Engineered bone grafts have been generated in static and dynamic systems by seeding and culturing osteoblastic cells on 3-D scaffolds. Seeding determines initial cellularity and cell spatial distribution throughout the scaffold, and affects cell-matrix interactions. Static seeding often yields low seeding efficiencies and poor cell distributions; thus creating a need for techniques that can improve these parameters.