Biomedical subjects

Young Ha Kim

Publications and source records attributed to Young Ha Kim.

At least 19 recordsLinked to original sources

PubMed2006

Complement activation by sulfonated poly(ethylene glycol)-acrylate copolymers through alternative pathway.

Previously, novel poly(ethylene glycol) (PEG) and sulfonated PEG acrylate (PEG-SO(3)A/OA) copolymers were prepared as coating and/or blending materials for biomedical applications. Surfaces modified with copolymers exhibited increased anti-coagulation properties and decreased plasma adsorption level due to increased hydrophilic properties and reorientation characteristics of PEG/PEG-SO(3)A chains in water phase. As continuation study, anti-complement effects of PEG-SO(3)/OA copolymers were investigated in vitro, and compared with those of low-density polyethylene (LDPE) and PEG/OA. C3 activation by PEG-SO(3)/OA samples was lower than that by PEG/OA samples, which was attributed to decreased surface nucleophile level of samples. PEG-SO(3)/OA samples increased inhibition of Bb production, resulting in decreased C5 activation. Owing to reduced activations of C3 and C5, PEG-SO(3)/OA samples markedly decreased SC5b-9 levels in plasma.

Acrylates↗

PubMed2006

RNAi-based knockdown of HBx mRNA in HBx-transformed and HBV-producing human liver cells.

RNA interference (RNAi) is the process of sequence-specific gene silencing induced by 21-23-nt RNA of small interfering RNA (siRNA). The HBx of hepatitis B virus (HBV) causing human liver diseases has been known as a multifunctional protein which affects transcription, cell growth, and apoptotic cell death. Here, we demonstrate that the HBx-specific siRNA (siRNAx) and short hairpin RNA (shRNAx) effectively induce the degradation of HBx mRNA in HBx-transformed and HBV-producing human liver cells by up to 80-90%. Also, the HBx expression in HBx-transformed cells was continuously silenced by retransformation with the shRNAx expression vector. These results imply that HBx-driven RNAi, either delivery of siRNAx or expression of shRNAx, provides a promising anti-HBV approach to suppress the HBx expression in human hepatoma cells.

Base Sequence↗

PubMed2006

New technique of seeding chondrocytes into microporous poly(L-lactide-co-epsilon-caprolactone) sponge by cyclic compression force-induced suction.

The initial requirement for a functional engineered cartilage tissue is the effective and reproducible seeding of chondrocytes into the interior of microporous scaffolds. High seeding efficiency, high cell viability, uniform cell distribution, and short operation time are also essential. We devised a new technique of seeding rabbit chondrocytes into microporous poly(L-lactide-co-epsilon-caprolactone) (PLCL) (porosity, 71- 80%; wall thickness, 2 and 6 mm) sponges under compression force-induced suction using a custom designed loading apparatus. Cell distribution and cell viability were determined using confocal laser scanning microscopy with fluorescent dye-staining techniques. Factors that affect the quality of a cell seeded construct were studied, namely, the porosity and thickness of sponges and suction cycles. Under 1 cycle of suction, an increase in porosity promoted cell seeding efficiency (CSE; defined as the percentage of the number of cells in the sponges relative to the initial number of cells seeded), cell viability (at 1 day post seeding), and a relatively uniform cell distribution, whereas thick sponges exhibited an inhomogeneous cell distribution irrespective of incubation time. Multiple cycles of suction of 5 and 10 at 0.1 Hz significantly improved the CSE, whereas high cell viability was maintained and even spatial cell distribution was achieved in 1 week. This study revealed that our newly developed cell seeding technique with multiple cycles of suction is a promising approach to inoculating cells into microporous sponges with high CSE, high cell viability, and homogeneous cell distribution.

Animals↗

PubMed2006

Mechano-active scaffold design based on microporous poly(L-lactide-co-epsilon-caprolactone) for articular cartilage tissue engineering: dependence of porosity on compression force-applied mechanical behaviors.

An essential component of functional articular cartilage tissue engineering is a mechano-active scaffold, which responds to applied compression stress and causes little permanent deformation. As the first paper of a series on mechano-active scaffold-based cartilage tissue engineering, this study focused on mechanical responses to various modes of loading of compression forces and subsequent selection of mechano-active scaffolds from the biomechanical viewpoint. Scaffolds made of elastomeric microporous poly(L-lactide-co-epsilon-caprolactone) (PLCL) with open-cell structured pores (300 approximately 500 microm) and with different porosities ranging from 71 to 86% were used. The PLCL sponges and rabbit articular cartilage tissue were subjected to compression/unloading tests (0.1 and 0.005 Hz) at 5 kPa, and stress relaxation tests at 10, 30, and 50% strain. The measurements of the maximum strain under loading and residual strain under unloading for compression tests and the maximum stress and equilibrium stress in the stress relaxation test showed that the lower the porosity, the closer the mechanical properties are to those of native cartilage tissue. Among the PLCL sponges, the sponge with 71% porosity appears to be a suitable cartilage scaffold.

Animals↗

PubMed2006

In vivo biocompatibility of sulfonated PEO-grafted polyurethanes for polymer heart valve and vascular graft.

Sulfonated poly(ethylene oxide) (PEO)-grafted polyurethane (PU) (PU-PEO-SO(3)) prepared by bulk modification was used to coat both PU heart valves and vascular grafts, and their in vivo biocompatibility was evaluated using a canine shunt method. The two devices were implanted for up to 39 days and retrieved at specific time points for the analysis of blood compatibility, biostability, and calcium deposition. When the surface of the retrieved specimens was examined using scanning electron microscopy, platelet adhesion and thrombus formation appeared to be significantly lesser formed on the PU-PEO-SO(3)-coated implants, compared with the untreated PUs. While molecular weights of untreated PUs were found by gel permeation chromatography to be decreased after 39 days from implantation, the same remained barely changed with the PU-PEO-SO(3)-coated ones. The inductively coupled plasma study indicated that the amount of deposited calcium was significantly reduced in the surface-modified PU implants. The efficacy of PU-PEO-SO(3)-coated implants in terms of blood compatibility, biostability, and calcification resistance may render them as a promising biomedical material in the application for blood/tissue-contacting tissues and organs.

Animals↗

PubMed2005

Mechano-active tissue engineering of vascular smooth muscle using pulsatile perfusion bioreactors and elastic PLCL scaffolds.

Blood vessels are subjected in vivo to mechanical forces in a form of radial distention, encompassing cyclic mechanical strain due to the pulsatile nature of blood flow. Vascular smooth muscle (VSM) tissues engineered in vitro with a conventional tissue engineering technique may not be functional, because vascular smooth muscle cells (VSMCs) cultured in vitro typically revert from a contractile phenotype to a synthetic phenotype. In this study, we hypothesized that pulsatile strain and shear stress stimulate VSM tissue development and induce VSMCs to retain the differentiated phenotype in VSM engineering in vitro. To test the hypothesis, rabbit aortic smooth muscle cells (SMCs) were seeded onto rubber-like elastic, three-dimensional PLCL [poly(lactide-co-caprolactone), 50:50] scaffolds and subjected to pulsatile strain and shear stress by culturing them in pulsatile perfusion bioreactors for up to 8 weeks. As control experiments, VSMCs were cultured on PLCL scaffolds statically. The pulsatile strain and shear stress enhanced the VSMCs proliferation and collagen production. In addition, a significant cell alignment in a direction radial to the distending direction was observed in VSM tissues exposed to radial distention, which is similar to that of native VSM tissues in vivo, whereas VSMs in VSM tissues engineered in the static condition randomly aligned. Importantly, the expression of SM alpha-actin, a differentiated phenotype of SMCs, was upregulated by 2.5-fold in VSM tissues engineered under the mechano-active condition, compared to VSM tissues engineered in the static condition. This study demonstrates that tissue engineering of VSM tissues in vitro by using pulsatile perfusion bioreactors and elastic PLCL scaffolds leads to the enhancement of tissue development and the retention of differentiated cell phenotype.

Animals↗

PubMed2005

Vascular patches tissue-engineered with autologous bone marrow-derived cells and decellularized tissue matrices.

Synthetic polymer vascular patches used in cardiovascular surgery have shortcomings such as thrombosis, intimal hyperplasia, calcification, infection, and no growth potential. Tissue-engineered vascular patches using autologous vascular cells may solve these problems. In this study, we developed a tissue-engineered vascular patch using autologous bone marrow-derived cells (BMCs) and decellularized tissue matrices. Vascular smooth muscle cells and endothelial cells were differentiated from bone marrow mononuclear cells in vitro. Tissue-engineered vascular patches were fabricated by seeding these cells onto decellularized canine inferior vena cava matrices and implanted into the inferior vena cava of dogs. Three weeks after implantation, the tissue-engineered vascular patches were patent with no sign of thrombus formation. Histological, immunohistochemical, and electron microscopic analyses of the vascular patches retrieved 3 weeks after implantation revealed regeneration of endothelium and smooth muscle and the presence of collagen and elastin. BMCs labeled with a fluorescent dye prior to implantation were detected in the retrieved vascular patches, indicating that the BMCs survived after implantation and contributed to the vascular tissue regeneration. This study demonstrates that vascular patches can be tissue-engineered with autologous BMCs and decellularized tissue matrices.

Animals↗

PubMed2005

In situ fabrication of self-transformable and hydrophilic poly(ethylene glycol) derivative-modified polysulfone membranes.

A self-transformable sulfonated poly(ethylene glycol) acrylate diblock copolymer (PEG-SO3A/OA) entrapped into polysulfone membrane was studied. The asymmetric membrane structure was prepared by a phase inversion process. The induced hydrophilicity by reorientation of diblock copolymer at the interface was evaluated by contact angle measurement, platelet adhesion test, and electron spectroscopy for chemical analysis (ESCA) depth profiling with ion sputtering. Molecular dynamic (MD) simulations as a function of copolymer density were also performed to obtain optimum interfacial structure information. The dependency of water clustering behavior as a hydrophilicity parameter was described in terms of an atom-atom radial distribution function (RDF). The results showed that the sulfonated diblock copolymer enhanced the hydrophilicity and long-term stability more than the copolymer having no hydrophobic block. Also, according to the ESCA, oxygen composition significantly began to decrease along the membrane depth, indicating the reorientation of diblock chains. The copolymer-entrapped surfaces significantly induced the degree of water clustering, and the resulting equilibrium rearrangement of interfacial structure was distinctly dependent upon the density of the copolymer.

Biocompatible Materials↗

PubMed2005

A poly(lactic acid)/calcium metaphosphate composite for bone tissue engineering.

A new method to prepare PLA/CMP (poly-L-lactide/calcium metaphosphate) composite scaffolds was developed for effective bone tissue engineering. This novel sintering method is composed of pressing the mixture of PLA, CMP, and salt particles at 150 MPa for 3 min followed by heat treatment at 210 degrees C for 30 min. The scaffolds had a homogeneously interconnected porous structure without a skin layer, and they exhibited a narrower pore size distribution and higher mechanical strength in comparison with scaffolds made by a solvent casting method. The scaffolds were seeded by osteoblasts and cultured in vitro or implanted into nude mice subcutaneously for up to 5 weeks. The number of cells attached to and proliferated on the scaffolds at both in vitro and in vivo was in the order of; PLA by novel sintering < PLA/CMP by solvent casting < PLA/CMP by novel sintering. In addition, the alkaline phosphatase activity of and calcium deposition in the scaffolds explanted from mice were enhanced significantly for the scaffolds by novel sintering compared to them by solvent casting. The in vitro results agreed well with the in vivo data. Such a superior characteristic of the novel sintering method should have resulted from the fact that the CMP particles could contact directly with cells/tissues to stimulate the cell proliferation and osteogenic differentiation, while the CMP particles would be coated by polymers and hindered to interact with cells/tissues in the case of a solvent casting method. As the novel sintering method does not use any solvents it offers another advantage to avoid problems associated with solvent residue.

Animals↗

PubMed2004

Thermally produced biodegradable scaffolds for cartilage tissue engineering.

A novel process was developed to fabricate biodegradable polymer scaffolds for tissue engineering applications, without using organic solvents. Solvent residues in scaffolds fabricated by processes involving organic solvents may damage cells transplanted onto the scaffolds or tissue near the transplantation site. Poly(L-lactic acid) (PLLA) powder and NaCl particles in a mold were compressed and subsequently heated at 180 degrees C (near the PLLA melting temperature) for 3 min. The heat treatment caused the polymer particles to fuse and form a continuous matrix containing entrapped NaCl particles. After dissolving the NaCl salts, which served as a porogen, porous biodegradable PLLA scaffolds were formed. The scaffold porosity and pore size were controlled by adjusting the NaCl/PLLA weight ratio and the NaCl particle size. The characteristics of the scaffolds were compared to those of scaffolds fabricated using a conventional solvent casting/particulate leaching (SC/PL) process, in terms of pore structure, pore-size distribution, and mechanical properties. A scanning electron microscopic examination showed highly interconnected and open pore structures in the scaffolds fabricated using the thermal process, whereas the SC/PL process yielded scaffolds with less interconnected and closed pore structures. Mercury intrusion porosimetry revealed that the thermally produced scaffolds had a much more uniform distribution of pore sizes than the SC/PL process. The utility of the thermally produced scaffolds was demonstrated by engineering cartilaginous tissues in vivo. In summary, the thermal process developed in this study yields tissue-engineering scaffolds with more favorable characteristics, with respect to, freedom from organic solvents, pore structure, and size distribution than the SC/PL process. Moreover, the thermal process could also be used to fabricate scaffolds from polymers that are insoluble in organic solvents, such as poly(glycolic acid). Cartilage tissue regenerated from thermally produced PLLA scaffold.

Animals↗

PubMed2004

Ring-opening polymerization of L-lactide and preparation of its microsphere in supercritical fluids.

The ring-opening polymerization of L-lactide initiated by stannous octoate was carried out in supercritical chlorodifluoromethane (scR22) at various reaction conditions (time and temperature) and reactant concentrations (initiator, monomer, and solvent). The monomer conversion increased to ca. 70% on increasing the reaction time to 1 h. The molecular weight of the poly(L-lactide) (PLLA) product also increased to ca. 160,000 g x mol(-1) over the same period. Increasing reaction temperature from 90 to 130 degrees C resulted in increased monomer conversion and PLLA molecular weight. A series of polymerizations conducted at various 1-dodecanol and stannous octoate concentrations suggested that stannous octoate does not act as an initiator by itself, and that the tin-alkoxide formed from 1-dodecanol and stannous octoate serves as the initiating species in scR22. While enhancements of the monomer conversion and PLLA molecular weight were observed with increasing monomer concentration, the chlorodifluoromethane concentration had the opposite on both. After the polymerization, PLLA microspheres were prepared in situ by using a continuous supercritical antisolvent process without residual organic solvent and monomer to yield highly purified microspheres for environmental and biomedical applications.

Chromatography, Supercritical Fluid↗

PubMed2004

Smooth muscle-like tissues engineered with bone marrow stromal cells.

Bone marrow-derived cells have demonstrated the ability to differentiate into multiple mesenchymal cell lineages. Here we tested whether smooth muscle (SM)-like tissues can be created in vivo with bone marrow stromal cells (BMSCs). Cultured canine BMSCs, which expressed SM cell-specific markers including SM alpha-actin and SM myosin heavy chain, were seeded on three-dimensional, biodegradable polymer scaffolds and implanted into peritoneal cavity of athymic mice. The cell-scaffold constructs retrieved 4 weeks after implantation formed three-dimensional tissues. Immunohistochemical analyses showed that the tissue reconstructs expressed SM alpha-actin and SM myosin heavy chain. Masson's trichrome staining showed the presence of significant amounts of collagen in the tissue reconstructs. Cells labeled with a fluorescent tracer prior to implantation were still present in the tissue reconstructs 4 weeks after implantation. Non-seeded scaffolds (control groups) retrieved 4 weeks after implantation did not exhibit extensive tissue formation. This study demonstrates the potential of BMSCs as an alternative cell source for tissue engineering of SM.

Absorbable Implants↗

PubMed2004

In vivo biocompatibilty and degradation behavior of elastic poly(L-lactide-co-epsilon-caprolactone) scaffolds.

Tubular scaffolds were fabricated from very elastic poly(L-lactide-co-epsilon-caprolactone) (PLCL, 50:50). The scaffolds were seeded with smooth muscle cells (SMCs) and implanted in nude mice to investigate the tissue compatibility and in vivo degradation behavior. Histological examination of all the implants with haematoxylin and eosin staining, masson trichrome staining, SM alpha-actin antibody, and CM-DiI labeling confirmed that the regular morphology and biofunction of the SMCs seeded and the expression of the vascular smooth muscle matrices in PLCL scaffolds. The implanted PLCL scaffolds displayed a slow degradation on time, where caprolactone units were faster degraded than lactide did. This could be explained by the fact that amorphous regions composed of mainly CL moieties degraded earlier than hard domains where most of the LA units were located. From these results, the scaffolds applied in this study were found to exhibit excellent tissue compatibility to SMCs and might be very useful for vascular tissue engineering.

Animals↗

PubMed2004

Manufacture of elastic biodegradable PLCL scaffolds for mechano-active vascular tissue engineering.

A soft and very elastic poly(lactide-co-epsilon-caprolactone) (PLCL)(50:50, Mn 185 x 10(3)) was synthesized. Tubular scaffolds were prepared by an extrusion-particulate leaching method for mechano-active vascular tissue engineering. The copolymer was very flexible but completely rubber-like elastic. Even the high porous PLCL scaffolds (90% salt wt) exhibited 200% elongation, but recovery over 85% in a tensile test. Moreover, the PLCL scaffolds maintained their high elasticity also in culture media under cyclic mechanical strain conditions. The highly porous scaffold (90% salt wt) withstood for an initial 1 week without any deformation and sustained for 2 weeks in culture media under cyclic stress of 10% amplitude and at 1 Hz frequency which are similar to the natural vascular conditions. Vascular smooth muscle cells (VSMCs) were seeded on to the PLCL scaffolds. The cell adhesion and proliferation on the scaffolds of various pore-size were increased with increasing pore size. For the pore sizes of 50-100 microm, 100-150 microm, 150-200 microm and 200-250 microm, the ratios of cell numbers were about 1:1.2:1.9:2.2, respectively, at both 12 h and 5 days. Similarly, the higher porous scaffolds exhibited more cell adhesion and proliferation compared to lower porous one, where the effect was more pronounced in the longer proliferation period. SMC-seeded scaffolds were implanted subcutaneously in athymic nude mice to confirm the biocompatibility. Such a high elastic property and proper biocompatibility to SMCs of PLCL scaffolds prepared in this study will be very useful to engineer SM-containing tissues such as blood vessels under mechanically dynamic environments (mechano-active tissue engineering).

Animals↗

PubMed2003

In vitro biocompatibility assessment of sulfonated polyrotaxane-immobilized polyurethane surfaces.

Sulfonated polyrotaxanes (PRx-SO(3)'s), in which sulfonated alpha-cyclodextrins (alpha-CDs) were threaded onto the poly(ethylene glycol) (PEG) segments in a PEG-b-poly(propylene glycol) (PPG)-b-PEG triblock copolymer (Pluronic) capped with benzyloxycarbonyl (Z)-L-phenylalanine (Z-L-Phe), were prepared as a novel surface-modifying biomaterial. Surface modification of the polyurethane (PU) was carried out by blending the PRx-SO(3)'s with a PU solution, followed by solution casting. The incorporated PRx-SO(3)'s led to the enhanced hydrophilicity by changing the surface properties of the PU matrix. Modified PUs showed the stable entrapment of the PRx-SO(3)'s with little extraction into water and enhanced mechanical properties after exposure to water compared to the PU control. The incorporated PRx-SO(3)'s repelled the proteins and kept them from closely approaching the surface areas, prevented platelet activation by thrombin, and effectively repelled bacteria. These results suggest that both the supramolecular structure of the polyrotaxanes and exposure of the sulfonated groups onto the surfaces contribute to these phenomena. Thus, surface modification with PRx-SO(3)'s is suggested to be useful for the fabrication of biocompatible medical devices.

Biocompatible Materials↗

PubMed2003

Elastic biodegradable poly(glycolide-co-caprolactone) scaffold for tissue engineering.

Cyclic mechanical strain has been demonstrated to enhance the development and function of engineered smooth muscle (SM) tissues, and it would be necessary for the development of the elastic scaffolds if one wishes to engineer SM tissues under cyclic mechanical loading. This study reports on the development of an elastic scaffold fabricated from a biodegradable polymer. Biodegradable poly(glycolide-co-caprolactone) (PGCL) copolymer was synthesized from glycolide and epsilon-caprolactone in the presence of stannous octoate as catalyst. The copolymer was characterized by (1)H-NMR, gel permeation chromatography and differential scanning calorimetry. Scaffolds for tissue engineering applications were fabricated from PGCL copolymer using the solvent-casting and particle-leaching technique. The PGCL scaffolds produced in this fashion had open pore structures (average pore size = 250 microm) without the usual nonporous skin layer on external surfaces. Mechanical testing revealed that PGCL scaffolds were far more elastic than poly(lactic-co-glycolic acid) (PLGA) scaffolds fabricated using the same method. Tensile mechanical tests indicated that PGCL scaffolds could withstand an extension of 250% without cracking, which was much higher than withstood by PLGA scaffolds (10-15%). In addition, PGCL scaffolds achieved recoveries exceeding 96% at applied extensions of up to 230%, whereas PLGA scaffolds failed (cracked) at an applied strain of 20%. Dynamic mechanical tests showed that the permanent deformation of the PGCL scaffolds in a dry condition produced was less than 4% of the applied strain, when an elongation of 20% at a frequency of 1 Hz (1 cycle per second) was applied for 6 days. Moreover, PGCL scaffolds in a buffer solution also had permanent deformations less than 5% of the applied strain when an elongation of 10% at a frequency of 1 Hz was applied for 2 days. The usefulness of the PGCL scaffolds was demonstrated by engineering SM tissues in vivo. This study shows that the elastic PGCL scaffolds produced in this study could be used to engineer SM-containing tissues (e.g. blood vessels and bladders) in mechanically dynamic environments.

Absorbable Implants↗

PubMed2003

Enhanced blood compatibility of polymers grafted by sulfonated PEO via a negative cilia concept.

In our laboratory sulfonated PEO (PEO-SO(3)) was designed as a "negative cilia model" to investigate a synergistic effect of PEO and negatively charged SO(3) groups. PEO-SO(3) itself exhibited a heparin-like anticoagulant activity of 14% of free heparin. Polyurethane grafted with PEO-SO(3) (PU-PEO-SO(3)) increased the albumin adsorption to a great extent but suppressed other proteins, while PU-PEO decreased the adsorption of all the proteins. The platelet adhesion was decreased on PU-PEO but least on PU-PEO-SO(3) to demonstrate an additional effect of SO(3) groups. The enhanced blood compatibility of PU-PEO-SO(3) in the ex vivo rabbit and in vivo canine implanting tests was confirmed. Furthermore, PU-PEO-SO(3) exhibited an improved biostability and suppressed calcification in addition to the enhanced antithrombogenicity. The in vivo antithrombogenicity and biostability were improved in the order of PU PU-PEO>PU-PEO-SO(3) in spite of the possible attraction between negative SO(3) groups and positive calcium ions. The bioprosthetic tissue (BT) was grafted with H(2)N-PEO-SO(3) via glutaraldehyde (GA) residues after conventional GA fixation. BT-PEO-SO(3) also displayed the decreased calcification by in vivo animal models. The application of PEO-SO(3) was extended by designing amphiphilic copolymers containing PEO-SO(3) moiety and hydrophobic long alkyl groups as anchors. The superior effect of PEO-SO(3) groups on thromboresistance compared to PEO was confirmed also in the case of copolymers coated or blended with other polymers and the systems coupled by UV irradiation, photoreaction or gold/sulfur or silane coupling technology, and therefore it might be very useful for the medical devices.

Adsorption↗

PubMed2003

A novel chemical modification of bioprosthetic tissues using L-arginine.

A novel chemical modification of biological tissues was developed by the direct coupling of bioactive molecule, L-arginine to bovine pericardium (BP). The modification involves pretreatment of BP using GA and followed by grafting arginine to BP by the reaction of residual aldehyde and amine group of L-arginine. BP was modified by direct coupling of bioactive molecules and the effect of L-arginine coupling on calcification and biocompatibility was evaluated in vitro and in vivo. Modified BPs were characterized by measuring shrinkage temperature, mechanical properties, digestion resistance to collagenase enzyme, in vitro plasma protein adsorption and platelet adhesion, and in vivo calcification. Thermal and mechanical properties showed that the durability of arginine treated tissue increased as compared with fresh tissue and GA treated tissue. Resistance to collagenase digestion revealed that modified tissues have greater resistance to enzyme digestion than did fresh tissue and GA treated tissue. Lower protein adsorption and platelet adhesion were observed on modified tissue than non-modified tissue. In vivo calcification study demonstrated much less calcium deposition on arginine treated BP than GA treated one. Obtained results attest to the usefulness of L-arginine treated BP for cardiovascular bioprostheses.

Animals↗