Hemodialysis membrane was prepared with polyamide6 via electrospinning technology for portable or wearable hemodialysis machine. Polyamide6 polymer solution was formed nanofiber membrane with fiber diameter of 72 ㎚, pore size 140 ㎚. Polyamide6 nanofiber membrane was chemically modified to enhance hemodialysis performance. Modified polyamide6 membrane showed an excellent hemodialysis performance and antifouling resistance against protein supplements by the esterification and crosslinking reaction.

In this study investigated a facile method to prepare modified hydrophilic polypropylene-grafted-maleic anhydride/polyamide 6 (PP-grafted-MAH/PA6), poly(methyl methacrylate) (PMMA) substrate and polyvinyl alcohol-chitosan (PVA-Chitosan) nanofiber membranes for selective urea and excess water flux under various conditions. Fiber diameters and pore sizes were controlled via electrodeposition spinning. The prepared membranes were applied to blood-dialysis membrane, such and a high water and urea flux of 150-250 mg/g membranes were found under the defined optimum conditions. Smaller fiber diameter with a mesopore density increased the efficiency of urea and water flux in blood. In the as-prepared smart membranes showed high flux capacity and selectivity, and promising demonstration.

The Ti-6Al-4V extra low interstitial (ELI) alloy has been widely used as an orthopedic implant material because of its excellent mechanical properties and biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity of the Al and V elements. Therefore, non-toxic biomaterials with a low elastic modulus need to be developed. A high energy mechanical milling (HEMM) process is introduced to improve the effect of sintering. Rapid sintering of spark plasma sintering (SPS) under pressure was used to make an ultra fine grain of Ti-25 wt.%Nb-7 wt.%Zr-10 wt.%Mo-(10 wt.%CPP) composites with bio-attractive elements for increasing strength. These composites were fabricated by SPS at 1000˚C at 60 MPa using HEMM powders. During the sintering process, CaTiO3, TixOy, and CaO were formed because of the reaction between Ti and CPP. The effects of CPP content on the physical and mechanical properties of the sintered Ti-Nb-Zr-Mo-CPP composites were investigated. The biocompatibility and corrosion resistance of the Ti-Nb-Zr-Mo alloys were improved by the addition of CPP.

Ti-6Al-4V ELI (Extra Low Interstitial) alloy has been widely used as an alternative to bone due to its excellent biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity. Therefore, nontoxic biomaterials with a low elastic modulus should be developed. However, the fabrication of a uniform coating is challenging. Moreover, the coating layer on Ti and Ti alloy substrates can be peeled off after implantation. To overcome these problems, it is necessary to produce bulk Ti and Ti alloy with hydroxyapatite (HA) composites. In this study, Ti, Nb, and Zr powders, which are biocompatible elements, were milled in a mixing machine (24h) and by planetary mechanical ball milling (1h, 4h, and 6h), respectively. Ti-35%Nb-7%Zr and Ti-35%Nb-7%Zr-10%HA composites were fabricated by spark plasma sintering (SPS) at 1000˚C under 70MPa using mixed and milled powders. The effects of HA addition and milling time on the biocompatibility and physical and mechanical properties of the Ti-35%Nb-7%Zr-(10%HA) alloys have been investigated. Ti2O, CaO, CaTiO3, and TixPy phases were formed by chemical reaction during sintering. Vickers hardness of the sintered composites increases with increased milling time and by the addition of HA. The biocompatibilty of the HA added Ti-Nb-Zr alloys was improved, but the sintering ability was decreased.

Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (μ-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.

목적: 실리콘은 생체적합성과 기체투과성 등의 특성을 가지고 있어 의료용 목적으로 많이 사용되고 있다. 이에 본 연구에서는 콘택트렌즈에 적용 가능한 실리콘의 합성과 그 응용에 있다. 방법: HEMA(2-hydroxyethyl methacrylate)를 사용하여 Acrylate-PDMS(Polydime-thylsiloxane) prepolymer를 합성하였다. 여기에 Phenyltrimethoxysilane을 비율별로 사용하였다. 촉매제로는 HCl를 사용하였으며, Na2CO3 수용액으로 촉매를 중화시켰다. 또한 DIW 제거를 위해 MgSO4를 사용하였다. 결과: FT-IR을 통하여 Poly Dimethylsiloxane에 Acrylate와 Phenyl이 Modification 되었음을 확인하였다. 결론: 합성된 Polydimethylsiloxane을 이용하여 기존의 친수성을 갖는 콘택트렌즈 재료와의 공중합을 통해 기능성 콘택트렌즈로 응용될 수 있을 것으로 판단된다.

It is necessary to improve the esthetic and function in the patient with oral and maxillofacial bone defects. Synthetic bone substitute materials and anorganic bovine bone mineral(ABBM) have been used for clinical restoration. The purpose of this study was to observe the biocompatibility and bone formation of synthetic hydroxyapatite(SHA) and ABBM in hole of rabbit's tibia. After specimens with SHA and ABBM at 8 weeks were fixed in 10% neutral formalin solution, dehydrated, and embedded with spurr low viscosity, they were cut by 500um with slow diamond wheel saw and grinded up to 200um in thickness. These specimens were coated with carbon and examined with r efraction microscope for bone density. Refraction microscopic features of 8 weeks in synthetic HA showed network-like new bone forming trabecular pattern attached to resorbed HA. Less well calcified trabecular bone surrounding conglomerated HAs showed irregular arrangement of numerous osteocytes. There was not completely filled in defected area by new bone trabecular. New trabecular bone formation by ABBM was more prominent and completely compacted in defect hole at 8 weeks. It suggested that although bone formation activity of AMMB might be superior to that on synthetic HA, both group would be the good biocompatibility in this experiment.

Porous Ti implant samples were fabricated by the sintering of spherical Ti powders in a high vacuum furnace. To increase their surface area and biocompatibility, anodic oxidation and a hydrothermal treatment were then applied. Electrolytes in a mixture of glycerophosphate and calcium acetate were used for the anodizing treatment. The resulting oxide layer was found to have precipitated in the phase form of anatase TiO2 and nano-scaled hydroxyapatite on the porous Ti implant surface. The porous Ti implant can be modified via an anodic oxidation method and a hydrothermal treatment for the enhancement of the bioactivity, and current multi-surface treatments can be applied for use in a dental implant system.

This experiment was performed to study the biocompatibility of xenograft materials (ABBM. coralline HA). Both autogenous bone grafts and allogenic banked bone were frequently and successfully used to promote regeneration of parts of skeleton. The use of these types of grafts were limited by the cost of donor site operation for autogenous boneor by fear of the risk of infection of allogenic materials. Another type of graft is xenograft which include ABBM and coralline HA. For investigating the biocompatibility, generally many investigators used cancer cell lines or animal cell lines. But cancer cell lines and animal cell lines had functioned different metabolism from normal human cell. So the experiment used normal human osteoblast for compare the biocompatibility of ABBM with coralline HA which were fixed in 24 well base contained culture medium. After 1st, 3rd, 7th, 14th, 28th days, the culture medium were taken out and checked the concentrations ofcalcium( Ca), inorganic phosphate(IP) and alkaline phosphatase(ALP). In another method, histologic samples were investigated after 8weeks of xenograft materials implantated on rabbit's tibia, the bone was cut and made undecalcified ground samples and checked with fluorecent microscope, polarizing microscope, reflection electron microscope and electron probe microanalysis. The statistical results of concentrations (Ca, IP, ALP) of materials in the culture medium have decreasedby day's, which meant that xenograft materials were effective for bone remodelling. The concentrations in the culture medium of ABBM were lower than that of coralline HA, that meant that biocompatibility of ABBM were superior than that of coralline HA. Histologic samples showed that ABBM had better bone remodelling effect than coralline HA. ABBM showed good alizarin red marking lines, more deposition of Ca, IP, and dense color of bone around newly formed osteon and bone trabeculae. it was concluded that ABBM was more biocompatible than corallineHA in vivo and in vitro test

Since ancient Eygypt, various dental materials were used for lost teeth including gold. The key point of this materials were nontoxic to human body. Since early of 1990's, dental implant was done for recovery of maxillofacial defects. From middle of 1970's, osseointergation concept of implant was introduced and performed in dental field. Biocompatibility of titanium showed good effect for osseointergration but had some problems (Galvance current and toxic corrosion) with suprastructures such as gold crowns. This study was performed to make safe dental implants which have reduced Galvanic currents and corrosion. 3 kind of dental casting gold alloys (different Gold contents, 1㎝×1㎝×0.1㎝ plates.) were used as experimental group, while Titanium were used as control group. Normal human osteoblasts(NHOsts)were cultured during 1-4weeks for histologic study. For analysing the calcium(Ca), Phosphorus(P) and alkaline phosphatase(ALP), NHosts were cultred during 2-23days. After experiments, histologic finding were observed by LSM and SEM. Ca, P, ALP concentration by automatic biochemical analyzer were analyzed by ANOVA test and linear regression method. The results were as follows. Biocompatibility of dental casting gold alloys were similar to titianium alloys histolgically. Biochemical analysis of dental casting gold alloys had no significant difference to titianium alloy except AIGIS-Fine. We could conclude that biocompatibility of dental casting gold alloys with high contents of gold were superior to that of low contents and alloys with high contents of gold had no significant difference from titanium on NHost culture. Gold dental implant might be better than titanium implant due to similar biocompatibility and no galvanic currency.

Biodegradable films were prepared by solution blending method in the weight ratio of Chitosan and Algin for the purpose of useful bioimplants. The possibility of bioimplants, which prepared from natural polymers as a akin substitute and food wrapping materials were evaluated by measuring the biodegradability. these biodegradable films were inserted in the back of rats and their biodegradability was investigated by hematological change as a function of time. Rats study showed that low-Chitosan induced increments of monocyte and basophil after 48 hours of implantation. And medium-Chitosan showed increase of lymphocyte and decreased neutrophil counts after 48hours of implantation. Low, medium Chitosan showed high hemoglobin contents, medium and high Chitosan showed high hematocrit value after 48 hours of implantation. As a result, medium, high-Chitosan induced potential incompatibility in the tissue after 48 hours, but there was little effects to the akin inflammation. The values of biodegradable films, which prepared from natural polymers measured in this study were some satisfiable results at short period with those of ideal akin bioimplants and artificial skin.