Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice.
Authors: Guerreiro SG, Brochhausen C, Negrão R, Barbosa MA, Unger RE, Kirkpatrick CJ, Soares R, Granja PL
Abstract
The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. ...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Calcium orthophosphates and human beings: a historical perspective from the 1770s until 1940.
Authors: Dorozhkin SV
Abstract
The historical development of a scientific knowledge on calcium orthophosphates from the 1770s until 1940 is described. Many forgotten and poorly known historical facts and approaches have been extracted from old publications and then they have been analyzed, systematized and reconsidered from the modern point of view. The chosen time scale starts with the earliest available studies of 1770s (to the best of my findings, calcium orthophosphates had been unknown before), passes through the entire 19th century and finishes in 1940, because since then the amount of publications o...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Synthesis and characterization of biocompatible-nanohydroxyapatite crystals obtained by a modified sol-gel processing.
Authors: Figueroa IA, Novelo-Peralta O, Flores-Morales C, González-Tenorio R, Piña-Barba MC
Abstract
A modified sol-gel process for synthesizing nanocrystalline hydroxyapatite powders (nHA) for biomedical applications, using tetrahydrated calcium nitrate [Ca(NO(3))(2)∙4H(2)O] and phosphorous pentoxide [P(2)O(5)] as precursor, is presented and discussed. The powders were washed and heat-treated at different temperatures and then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The total process time reached with this modified proces...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
In vitro degradation and release characteristics of spin coated thin films of PLGA with a "breath figure" morphology.
Authors: Ponnusamy T, Lawson LB, Freytag LC, Blake DA, Ayyala RS, John VT
Abstract
Poly (lactic-co-glycolic acid) (PLGA) coatings on implant materials are widely used in controlled drug delivery applications. Typically, such coatings are made with non-porous films. Here, we have synthesized a thin PLGA film coating with a highly ordered microporous structure using a simple and inexpensive water templating "breath figure" technique. A single stage process combining spin coating and breath figure process was used to obtain drug incorporated porous thin films. The films were characterized by scanning electron...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Effect of cement fill ratio in loosening of hip implants.
This study has shown that there is an ideal thickness range between 2 to 5 mm that should be kept. From radiographic images one can measure the thickness of the cement mantle showing the loosening characteristics.
PMID: 23507806 [PubMed - indexed for MEDLINE] (Source: Biomatter)
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Evaluation of silicon nitride as a wear resistant and resorbable alternative for total hip joint replacement.
In this study, it was shown that α-Si(3)N(4)-powder dissolves in PBS. Adsorption of blood plasma indicated a good acceptance of Si(3)N(4) in the body with relatively low immune response. Si(3)N(4) sliding against Si(3)N(4) showed low wear rates both in bovine serum and PBS compared with the other tested wear couples. Tribofilms were built up on the Si(3)N(4) surfaces both in PBS and in bovine serum, controlling the friction and wear characteristics.
PMID: 23507807 [PubMed - indexed for MEDLINE] (Source: Biomatter)
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Biomimetic evaluation of β tricalcium phosphate prepared by hot isostatic pressing.
Authors: Mateescu M, Rguitti E, Ponche A, Descamps M, Anselme K
Abstract
Two types of completely densified β-TCP tablets were synthesized from a stoichiometric β-TCP powder. The first ones (TCP) were conventionally sintered, while the second ones (TCP-T) were sintered and treated by hot isostatic process (HIP). The HIP produced completely densified materials with relative densities greater than 99.9% and a transparent appearance of tablets. Samples were immersed in culture medium with (CM) or without serum (NCM) in static and dynamic conditions for a biomimetic evaluation. Similarly, SaOs-2 cells were cu...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Letter from the editor: improving biomaterials through matrix engineering.
Authors: Rammelt S
PMID: 23507862 [PubMed - indexed for MEDLINE] (Source: Biomatter)
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
New methods to study the composition and structure of the extracellular matrix in natural and bioengineered tissues.
Authors: Schiller J, Huster D
Abstract
The extracellular matrix (ECM) comprises a gel of numerous biopolymers that occurs in a multitude of biological tissues. The ECM provides the basic support and mechanical strength of skeletal tissue and is responsible for shape retention. At the same time, the ECM is responsible for the viscoelastic properties and the elasticity of soft tissues. As expected, there are several important diseases that affect and degenerate the ECM with severe consequences for its properties. Bioengineering is a promising approach to support the regenerative capacity of the body. Unfortu...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Functionalization of biomaterial surfaces using artificial extracellular matrices.
Authors: Bierbaum S, Hintze V, Scharnweber D
Abstract
Construction of biomaterials with the ability to guide cell function is a topic of high interest in biomaterial development. One approach is using components native to the ECM of the target tissue to generate in vitro a microenvironment that can also elicit specific responses in cells and tissues--an artificial ECM (aECM). The focus is on collagen as the basic material, which can be modified using a number of different glycoproteins, proteoglycans and glycosaminoglycans. Preparation, immobilization and the biochemical characteristics of such aECM are di...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Functional aspects of the interaction between interleukin-8 and sulfated glycosaminoglycans.
Authors: Pichert A, Schlorke D, Franz S, Arnhold J
Abstract
During the immune response, the cytokine interleukin 8 (IL-8, CXCL8) functions as a strong chemoattractant for polymorphonuclear leukocytes helping to direct these cells to infected/injured sites. This review focuses on the interaction of IL-8 with sulfated glycosaminoglycans expressed on cell surfaces and the extracellular matrix. This interaction contributes to the recruitment of polymorphonuclear cells from blood, penetration of these cells through the vessel wall, and their directed migration to inflammatory sites. Regulatory aspects of the in...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Surface modification of implants in long bone.
Authors: Förster Y, Rentsch C, Schneiders W, Bernhardt R, Simon JC, Worch H, Rammelt S
Abstract
Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure. This review presen...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Embroidered and surface coated polycaprolactone-co-lactide scaffolds: a potential graft for bone tissue engineering.
This article reviews a possible strategy using a tissue engineering approach and systematically describes a series of experiments evaluating the properties of an embroidered and surface coated polycaprolactone-co-lactide scaffold being considered as bone graft substitute for large bone defects. The scaffold design and fabrication, the scaffolds properties, as well as its surface modification and their influence in vitro are evaluated, followed by in vivo analysis of the scaffolds using orthotopic implantation models in small and large animals.
PMID: 23507867 [PubMed - indexed for MEDLINE] (Source: Biomatter)
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
The role of perfusion bioreactors in bone tissue engineering.
Authors: Gaspar DA, Gomide V, Monteiro FJ
Abstract
Tissue engineering has emerged as a possible alternative to current treatments for bone injuries and defects. However, the common tissue engineering approach presents some obstacles to the development of functional tissues, such as insufficient nutrient and metabolite transport and non-homogenous cell distribution. Culture of bone cells in three-dimensional constructs in bioreactor systems is a solution for those problems as it improves mass transport in the culture system. For bone tissue engineering spinner flasks, rotating wall vessels and perfusion sys...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
Infection of orthopedic implants with emphasis on bacterial adhesion process and techniques used in studying bacterial-material interactions.
Authors: Ribeiro M, Monteiro FJ, Ferraz MP
Abstract
Staphylococcus comprises up to two-thirds of all pathogens in orthopedic implant infections and they are the principal causative agents of two major types of infection affecting bone: septic arthritis and osteomyelitis, which involve the inflammatory destruction of joint and bone. Bacterial adhesion is the first and most important step in implant infection. It is a complex process influenced by environmental factors, bacterial properties, material surface properties and by the presence of serum or tissue proteins. Properties of the substrate, such as chem...
Source: Biomatter - November 20, 2015 Category: Biotechnology Tags: Biomatter Source Type: research
