Evaluation of the potential anti-adhesion effect of the PVA/Gelatin membrane (original) (raw)

2013-J Biomed Mater Res Part B Appl Biomater-2013

A new strategy to improve silicon-based endodontic treatment tightness by dentine hydrophobization is presented in this work: root dentine was silanized to obtain a hydrophobic dentine-sealer interface that limits fluid penetration. This strategy was based on the grafting of aliphatic carbon chains on the dentine through a silanization with the silane end groups [octadecyltrichlorosilane (OTS) and octadecyltriethoxysilane]. Dentine surface was previously pretreated, applying ethylenediaminetetraacetic acid and sodium hypochlorite, to expose hydroxyl groups of collagen for the silane grafting. Collagen fibers exposure after pretreatment was visible with scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy showed their correct exposition for the silanization (amide I and II, with 1630, 1580, and 1538 cm -1 peaks corresponding to the vibration of C¼ ¼O and CAN bonds). The grafting of aliphatic carbon chains was confirmed by FTIR (peaks at 2952 and 2923 cm -1 corresponding to the stretching of CAH bonds) and by the increasing of the water contact angle. The most efficient hydrophobization was obtained with OTS in ethyl acetate, with a water contact angle turning from 51 to 109 . Gas and liquid permeability tests showed an increased seal tightness after silanization: the mean gas and water flows dropped from 2.02 Â 10 -8 to 1.62 Â 10 À8 mol s -1 and from 10.8 Â 10 À3 to 5.4 Â 10 À3 mL min À1 , respectively. These results show clear evidences to turn hydrophilic dentine surface into a hydrophobic surface that may improve endodontic sealing. V C 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000-000, 2013.

Biomaterial properties of cholecyst-derived scaffold recovered by a nondetergent/enzymatic method

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014

Isolation procedures for the recovery of extracellular matrices (ECMs) from animal organs/tissues that are useful in regenerative medicine involve multiple sequential steps/stages including collection of the source organ at slaughter, their transportation to laboratory, decellularization, decontamination, stabilization, and sterilization. Most of these steps require extensive use of chemicals/reagents/enzymes which may also adversely affect the quality of the scaffold. With an effort to minimize the use of chemicals/reagents/enzymes, while extracting biomaterial-grade ECM from porcine cholecyst (gall bladder), we performed preisolation ex situ incubation of the organ in a stabilizing agent that also caused in situ crosslinking of tissue-components and delaminated the collagen-rich ECM from the tissue-layer beneath the mucosa. The physical, chemical, and biological properties of the isolated scaffolds were similar to that of a commercially available porcine small intestinal submucosa. The cholecyst-derived scaffold not only satisfied preclinical safety-test procedures such as cytotoxicity, local response, and endotoxin load but also showed the potential to promote healing of full-thickness skin wound in a rabbit model. The procedure was also suitable for isolating scaffolds from other hollow organs such as jejunum and urinary bladder. It was concluded that enzyme/detergent treatment may be an avoidable step while isolating biomaterialgrade scaffolds from hollow organs. V C 2014 Wiley Periodicals, Inc.

Biomimetic materials in tissue engineering

Materials Today, 2010

Cells receive numerous signals from their immediate microenvironment, the extracellular matrix (ECM) 1 . Within a biomechanical context provided by this elastic milieu 2 , cells adhere by receptor-mediated interactions with ECM components such as fibronectin and laminin (among many others, as reviewed elsewhere), mediated by specialized adhesion receptors such as integrins and others 3 . These receptors transmit stress from the ECM, through the membrane (the receptors are transmembrane proteins), to the cytoskeleton within the cell in a dynamic and concerted manner 4 . The adhesion receptors do much more than transmit stress, however; in particular within clusters of adhesion receptors in the membrane, biochemical signal transduction takes place through kinase activation and other mechanisms 3,4 . In addition to adhesion proteins, the ECM also sequesters and presents a number of morphoregulatory molecules including growth factors, which control processes of cell division, differentiation, and multicellular morphogenesis 2,5 .

Cell adhesion on artificial materials for tissue engineering

Physiological research / Academia Scientiarum Bohemoslovaca, 2004

Advanced interdisciplinary scientific field of tissue engineering has been developed to meet increasing demand for safe, functional and easy available substitutes of irreversibly damaged tissues and organs. First biomaterials were constructed as "two-dimensional" (allowing cell adhesion only on their surface), and durable (non-biodegradable). In contrast, biomaterials of new generation are characterized by so-called three dimensional porous or scaffold-like architecture promoting attachment, growth and differentiation of cells inside the material, accompanied by its gradual removal and replacement with regenerated fully functional tissue. In order to control these processes, these materials are endowed with a defined spectrum of bioactive molecules, such as ligands for adhesion receptors on cells, functional parts of natural growth factors, hormones and enzymes or synthetic regulators of cell behavior, incorporated in defined concentrations and spatial distribution against...

Evaluation of the antiadhesion potential of UV cross-linked gelatin films in a rat abdominal model

Biomaterials, 2002

Among five kinds of rat adhesion models tested, the following model was selected. The epigastric vein 2.5 cm from the midline of the abdomen was cut by sharp scissors, and the lateral side of the cut epigastric vein was ligated using a 3-0 silk suture. This model could be easily prepared and gave a rate of adhesion formation of 90%, which was useful for screening antiadhesive materials. For the kinetic study of tissue adhesion in this model, an injured site was covered with a non-degradable poly(vinyl alcohol) (PVA) film. The incidence rate of adhesion was 18%, when the PVA film covered the injured site for 2 days. This suggests that an antiadhesive barrier should cover the injured site for at least 2 days. The antiadhesion efficacy of cross-linked gelatin films were evaluated using this adhesion model. The UV cross-linked gelatin film which was designed to exist for 2 days but to disappear at day 3 in the rat abdominal cavity showed the highest antiadhesion efficacy. r

Polymers that reduce intraperitoneal adhesion formation

The British journal of surgery, 1998

BackgroundViscous macromolecules and phospholipids have been shown to reduce postoperative adhesion formation. The ideal agent, or combination of agents, still remains to be identified.Viscous macromolecules and phospholipids have been shown to reduce postoperative adhesion formation. The ideal agent, or combination of agents, still remains to be identified.MethodsThe effect of hydrophobically modified ethyl (hydroxyethyl) cellulose (HM-EHEC) and polyquarternium-24 (LM-200), two cellulose-derived polymers, and of sphingomyelin, was examined in an animal model. Adhesions were induced in the parietal peritoneum in a standardized manner and quantity, and the morphology of adhesion formation was evaluated after 7 days.The effect of hydrophobically modified ethyl (hydroxyethyl) cellulose (HM-EHEC) and polyquarternium-24 (LM-200), two cellulose-derived polymers, and of sphingomyelin, was examined in an animal model. Adhesions were induced in the parietal peritoneum in a standardized manner and quantity, and the morphology of adhesion formation was evaluated after 7 days.ResultsA significant reduction in adhesion formation was seen in animals receiving LM-200 (P = 0·013) and HM-EHEC (P = 0·012) as a short-term treatment compared with controls given saline, but not in animals receiving sphingomyelin (P = 0·733). Additional effects were seen in the animals receiving LM-200 as a prolonged treatment (P < 0·001) compared with controls. There was no difference in the magnitude of the inflammatory response between the groups.A significant reduction in adhesion formation was seen in animals receiving LM-200 (P = 0·013) and HM-EHEC (P = 0·012) as a short-term treatment compared with controls given saline, but not in animals receiving sphingomyelin (P = 0·733). Additional effects were seen in the animals receiving LM-200 as a prolonged treatment (P < 0·001) compared with controls. There was no difference in the magnitude of the inflammatory response between the groups.ConclusionThese results suggest that hydrophobically modified polymers are efficient in reducing adhesions, without affecting the inflammatory response. © 1998 British Journal of Surgery Society LtdThese results suggest that hydrophobically modified polymers are efficient in reducing adhesions, without affecting the inflammatory response. © 1998 British Journal of Surgery Society Ltd

Naturally Derived Biomaterials: Preparation and Application

Regenerative Medicine and Tissue Engineering, 2013

eliminating all cells from native tissues/organs. Physical, chemical and enzymatic approaches are combined to make the effective decellularization protocol. Because of their advantages, naturally derived biomaterials are usually applied to replace or restore structure and function of damaged tissues/organs. They have ability to adequately support cell adhesion, migration, proliferation and differentiation. In particular, when implanted into a defective area, naturally derived biomaterials can enhance the attachment and migration of cells from the surrounding environment, therefore, induce extracellular matrix formation and promote tissue repair. Some biomaterials are used to acting as drug delivery system and medical devices such as surgical sutures. The silk fiber produced by silkworm or spider has been used as a surgical suture for a long time due to its biodegradable and non-antigenic protein. These silk fibroin nanoparticles are the globules with a fine crystallinity that may offer various possibilities for surface modification and covalent drug attachment. Furthermore, some biomaterials are used to produce environmental friendliness of packaging (such as resorbable chitosan packing) and other products. Some commercial products were made from naturally derived biomaterial such as SIS, Matrigel, Alloderm… In this chapter, we focus on a brief knowledge as well as the methods of preparation and application of naturally derived biomaterials in our researches. 2. Naturally derived biomaterials: Preparation and application 2.1. Protein 2.1.1. Collagen 2.1.1.1. Structure Collagen is the most abundant protein of connective tissues in all animals. Now, at least sixteen types of collagen have been identified, in which 80-90% of the collagen is types I, II and III. Collagen is secreted by not only fibroblasts but also epithelial cells [1]. The basic structural unit of collagen is a triple helix. Most collagen is fibrillar because of pack of collagen molecules type I, II, III. Contrast, collagen IV forms a two dimensional network which is unique to the basement membranes [1]. Basement membranes have been performed a number of mechanical and biological functions. They provide physical support for tissue because of their tensile strength. They also influence cell proliferation, adhesion, migration, differentiation, polarization, and are thus implicated in biological processes such as development, tissue maintenance, regeneration, and repair, and in various pathological processes such as tumor growth and metastasis [2]. The basement membranes composition varies from one tissue to another. In general, the major constituents of all basement membranes are collagen IV, laminins, nidogen/entactin, and proteoglycans. The functional diversity of basement membranes arises from the molecular diversity of their components, particularly the different collagen IV and laminin isoforms [2].

Evolution of PVA gels prepared without crosslinking agents as a cell adhesive surface

Journal of Materials Science: Materials in Medicine, 2011

Physical parameters (such as crosslinking density, crystallinity and mechanical properties) have been found to largely affect cellular behavior on polymer scaffolds. This study demonstrated that transparent pure Poly (vinyl alcohol) hydrogels prepared via a freeze-thaw method can be made to support cell adhesion by controlling physical parameters such as concentration and the number of freeze-thaw cycles. For a given number of freeze-thaw cycles, (specifically 45), polymer concentration dependent structural and mechanical properties (such as tensile strength and stiffness) were correlated with cell adhesion. The maximum cell attachment occurred on the hydrogels with the greatest mechanical properties, crystallinity and crosslinking density. The hydrogel surfaces were more favorable to human dermal fibroblasts than human lens epithelial cells and retained their transparency as well as dimensional stability with only a small degree of swelling. Fibroblast laden hydrogels showed extensive alkaline phosphatase activity which confirmed their healthy proliferation and function. In this manner, this study suggests that transparent Poly (vinyl alcohol) hydrogels prepared by the freeze thaw method described here should be further studied for numerous tissue engineering applications.