Biomaterials In Reconstructive Surgery Research Articles

In vivo application of a glutaraldehyde-free, UVA/riboflavin cross-linked bovine pericardium confirms suitability for cardiovascular substitutes

Glutaraldehyde (GA)-treated bovine pericardium is still the gold standard for the fabrication of bioprostheses needed for the surgical treatment of valvular malfunction. Although excellent stability and low immunogenicity are accomplished, the application of GA is considered to be causal for structural valve deterioration, diminishing the long-term durability of bioprosthetic tissue. The novel GA-free SULEEI-treatment of bovine pericardium combines decellularization, riboflavin/UVA-cross-linking, and low-energy electron beam irradiation. In the present study, we initiated an in vivo application. We used a subcutaneous rat model to compare the immune and tissue responses, calcification propensity, and biomechanical properties of the alternatively prepared SULEEI bovine pericardial tissue with standard glutaraldehyde-fixed and industrially produced bovine pericardial patch material. SULEEI pericardium evokes a similar immune reaction and tissue response as the control standard bovine patch material. The calcification propensity of SULEEI tissue was low, and biomechanical analysis revealed a heterogeneous but similar pattern in tissue stiffness compared to the control patch. The results of this study highlight the potential of SULEEI-treated bovine pericardial tissue as a candidate for cutting-edge cardiovascular and valvular biomaterials in reconstructive surgery.

Materials based o tricalcium phosphate as bone defects substitute (literature review)

The objective of the study is to determine the current tendencies in the use of osteoplastic materials based on tricalcium phosphate (TCP) in orthopedics and traumatology. Methods. The search of the scientific information for the analysis was carried out in the PubMed, Google Scholar, World Digital Library, ScienceDirect. Results. The development of biomaterials for reconstructive surgery on the skeleton remains an urgent issue of biomaterial engineering, biology and current traumatology and orthopedics. Calcium-phosphate ceramics have the excellent properties of biocompatibility, affinity with bone tissue, biodegradability as well as perfect osteoconductive and osteointegrative properties. They are used in orthopaedics and traumatology as a coating for endoprosthesis components in order to achieve a strong bond with the bone as well as a filling material for bone defects in the form of blocks, granules or powder. The optimal structure of ceramic materials in order to achieve the necessary hardness and control of the dissolution rate is still undetermined. The interest of researchers in the creation of osteoplastic materials containing TCP is explained by the advanced osteoinductive properties and the ability to quickly degrade with the formation of bone tissue. Due to different configurations and sizes of the bone defects, the creation of a material with osteoinductive and osteoconductive properties that could be inserted into the cavity in a liquid state and which would quickly harden and acquire the properties similar to those of the bone has been of great current interest. The material should be biodegradable while having sufficient time for bone formation at the implantation site. In view of the above, the creation of cements based on calcium phosphates has become more attractive. Unfortunately, this material is limited in use due to its brittleness and insufficient hardness. Certain reinforcing additives are expected to significantly improve the mechanical properties of the cement. It is desirable that these particles should have bioactive properties analogous to those of cement. A slight modification of the material can significantly change its properties, which makes it imperative to investigate experimentally the biological properties of the investigated material.

Bladder augmentation and urinary diversions in kidney transplants

There is some controversy about the safety of kidney transplant in patients with augmented or diverted urinary system: they are considered higher risk recipients in view of increased technical problems and infective complications leading to pyelonephritis and graft loss. The ureter of a transplanted kidney should be anastomosed into a reservoir with an adequate capacity, with low bladder pressure, with good compliance, and efficient voluntary empting. Ileal and sigmoid bladder augmentation, usually associated with clean intermittent catheterization, has become a well-accepted part of the urological practice and has been used for implantation of the transplant ureter. During the last years, the interest in new biomaterials for reconstructive surgery has increased. Experimental studies showed how these requests can be satisfied by porcine small intestinal submucosa SIS (Stratasis™): this can be degraded by the host and substituted by "new tissue". In four recent cases we have used SIS to obtain an augmented, normalpressure and good compliance bladder reservoir, with three (epithelial, muscular and adventitial) layers normally represented.

Biocompatibility of porous polyethylene implants tissue‐engineered by extracellular matrix and VEGF

Rapid ingrowth of blood vessels and low inflammatory response are considered major prerequisites for successful implantation of biomaterials in reconstructive surgery. Aim of the present study was to evaluate whether tissue-engineered porous polyethylene (PPE) implants providing extracellular matrix components (ECM) and vascular endothelial growth factor (VEGF) in vivo improve microvascular ingrowth and mechanical integration with regard to initial inflammatory responses. PPE implants (3 x 3 x 0.1 mm(3), pore size approximately 100-200 microm) were tissue-engineered by incorporation of ECM components (GFR-Matrigel) adding recombinant murine VEGF (1 microg/mL) and grafted into dorsal skinfold chamber preparations of C57BL/6 mice. Control animals received uncoated implants or implants coated with ECM components alone (n = 6 per group). Using in vivo fluorescence microscopy angiogenic activity and inflammatory leukocyte-endothelial cell interactions were analyzed for 2weeks. Finally, mechanical integration was quantified by measurement of dynamic desintegration strengths at the host-implant border. Functional vessel density, red blood cell velocity, and vessel diameters increased continuously in all groups indicating that rapid microvascular integration of PPE occurred even without incorporation of ECM or VEGF. However, a transient initial inflammatory response with increased leukocyte-endothelial cell adherence on day 7 in uncoated control implants was efficiently reduced by incorporation of ECM and VEGF. Measurement of dynamic breaking strengths revealed no significant differences between the groups although there was a tendency to improved mechanical integration in tissue-engineered implants. Therefore, novel tissue- engineered constructs of PPE implants providing ECM and VEGF in high local concentrations can increase biocompatibility especially under unfavorable conditions for implantation.

Bladder Augmentation and Urinary Diversions in Kidney Transplants

There is some controversy about the safety of kidney transplant in patients with augmented or diverted urinary system: they are considered higher risk recipients in view of increased technical problems and infective complications leading to pyelonephritis and graft loss. The ureter of a transplanted kidney should be anastomosed into a reservoir with an adequate capacity, with low bladder pressure, with good compliance, and efficient voluntary empting. Ileal and sigmoid bladder augmentation, usually associated with clean intermittent catheterization, has become a well-accepted part of the urological practice and has been used for implantation of the transplant ureter. During the last years, the interest in new biomaterials for reconstructive surgery has increased. Experimental studies showed how these requests can be satisfied by porcine small intestinal submucosa SIS (Stratasis”): this can be degraded by the host and substituted by “new tissue”. In four recent cases we have used SIS to obtain an augmented, normal-pressure and good compliance bladder reservoir, with three (epithelial, muscular and adventitial) layers normally represented.

Biomaterials in Reconstructive Surgery

Biomaterials in Reconstructive Surgery

Biomaterials in Reconstructive Surgery

Biomaterials in Reconstructive Surgery

Biomaterials in reconstructive surgery

Biomaterials in reconstructive surgery