• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제41권
• /
• pp.47.1-47.10
• /
• 2019

Background: Hyaluronic acid (HA) has been applied as a primary biomaterial for temporary soft tissue augmentation and as a carrier for cells and the delivery of growth factors to promote tissue regeneration. Although HA derivatives are the most versatile soft tissue fillers on the market, they are resorbed early, within 3 to 12 months. To overcome their short duration, they can be combined with cells or growth factors. The purpose of this study was to investigate the stimulating effects of human fibroblasts and basic fibroblast growth factors (bFGF) on collagen synthesis during soft tissue augmentation by HA hydrogels and to compare these with the effects of a commercial HA derivative (Restylane^®). Methods: The hydrogel group included four conditions. The first condition consisted of hydrogel (H) alone as a negative control, and the other three conditions were bFGF-containing hydrogel (HB), human fibroblast-containing hydrogel (HF), and human fibroblast/bFGF-containing hydrogel (HBF). In the Restylane^® group (HGF), the hydrogel was replaced with Restylane^® (R, RB, RF, RBF). The gels were implanted subdermally into the back of each nude mouse at four separate sites. Twelve nude mice were used for the hydrogel (n = 6) and Restylane^® groups (n = 6). The specimens were harvested 8 weeks after implantation and assessed histomorphometrically, and collagen synthesis was evaluated by RT-PCR. Results: The hydrogel group showed good biocompatibility with the surrounding tissues and stimulated the formation of a fibrous matrix. HBF and HF showed significantly higher soft tissue synthesis compared to H (p < 0.05), and human collagen type I was well expressed in HB, HF, and HBF; HBF showed the strongest expression. The Restylane^® filler was surrounded by a fibrous capsule without any soft tissue infiltration from the neighboring tissue, and collagen synthesis within the Restylane^® filler could not be observed, even though no inflammatory reactions were observed. Conclusion: This study revealed that HA-based hydrogel alone or hydrogel combined with fibroblasts and/or bFGF can be effectively used for soft tissue augmentation.

• 대한의용생체공학회:의공학회지
• /
• 제40권4호
• /
• pp.137-142
• /
• 2019

Numerous efforts are being made to develop an ideal dermal filler that should be bio-compatibility, non-immunogenicity, long-lasting and biodegradable without a toxic secretion. Biomaterials of dermal fillers are hyaluronic acid filler, calcium filler, PMMA filler and collagen filler depending on the ingredient. Although hyaluronic acid (HA) is most widely used, it has shortages such as short shelf life and low mechanical strength compare to extracellular matrix (ECM). The cartilage ECM composed of collagen type II, proteoglycans, glycosaminoglycans (GAGs) and in a minor part with glycoproteins. In this study, we developed a cartilage ECM injectable filler capable of improving biocompatibility and longevity compared with hyaluronic acid (HA) fillers. The ECM hydrogel was cross-linked by the reaction of N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) for mechanical enhancement. Prepared ECM filler was compared with cross-linked HA by butanediol diglycidyle ether (BDDE), which is the most widely used natural polymers for dermal filler. In the results, the articular cartilage ECM hydrogel has great potential as a dermal filler to improve the biophysical and biological performance.

• 한국응용과학기술학회지
• /
• 제37권6호
• /
• pp.1773-1778
• /
• 2020

본 연구는 히알루론산을 함유한 온도 감응성 하이드로겔 마스크 팩을 이용하여 피부개선효과 및 사용감을 평가하였다. 임상시험 기준에 적합한 30~40대 여성 10명의 시험대상자에게 4주간 주3회 하이드로겔 마스크 팩을 적용하고 수분, 유분, 피부 톤을 측정하였다. 그 결과 피부 수분량은 1회 사용 후 11.3%, 4주 사용 후 58.36% 증가하였고, 유분량은 1회 사용 후 67% 증가 후 일정 값을 유지하고 더 이상 증가하지 않았다. 피부 톤은 4주 사용 후 좌우 뺨 모두 피부 톤이 밝아졌고 사용감 및 체감효능 평가는 87.6% 이상의 긍정적인 답변을 보였다. 이상의 결과로 하이드로겔 마스크 팩은 피부개선에 도움을 주는 우수한 소재로 판단된다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVI)
• /
• pp.557-557
• /
• 2005

• 센서학회지
• /
• 제21권4호
• /
• pp.256-262
• /
• 2012

Hyaluronic acid(HA) hydrogels were synthesized by immersing HA microbeads in phosphate buffered saline solutions having different pH levels to assess the effect of pH on the swelling ratio of HA hydrogels for smart drug delivery systems. No beads were formed when the HA solution(below pH 9) was crosslinked with divinyl sulfone(DVS) because DVS is a basic solution. The variation regarding the size of the microbead was not significant, suggesting that the bead size is not a function of pH(10 ~ 14). However, the pore size of the microbeads decreased with increasing pH from 10 to 14, leading to the surface smoothness and dense network as a result of higher crosslinking. The swelling ratio of hydrogels increased when the pH rose from 2(acidic) to 6(neutral). Afterwards, it decreased with further increasing pH(basic). The lower swelling ratio may be due to the lack of ionization of the carboxyl groups. On the other hand, a higher swelling ratio is likely due to the increased electrostatic repulsions between negatively charged carboxyl groups on different chains. Experimental results suggested that pH-responsive HA hydrogels can be applicable to the controlled drug delivery systems.

• 대한의용생체공학회:의공학회지
• /
• 제34권3호
• /
• pp.117-122
• /
• 2013

Hyaluronic acid(HA) microbeads were synthesized by dropping the sodium hyaluronate(Streptococcus) solutions in NaOH into a solution mixture of divinyl sulfone(DVS) in 2-methyl-1-propanol, followed by stirring, cleaning and drying process at room temperature. The initial experimental conditions are crosslinking time(CLTi) of 5 h, crosslinking temperature(CLTe) of room temperature, injection air pressure(IAPr) of 5 psi, and DVS concentration( DVSc) of 0.2 vol%, respectively. Then, parametric studies were performed by varying the parameters to investigate the morphology, the porosity, the swelling ratio and the size of the beads. The microbead size pattern was not regular to function of the degree of crosslink. It was observed that the swelling ratio, the degree of crosslink, and the pore size can be controlled by adjusting the CLTi, CLTe and DVSc. Among the parameters investigated, the smallest bead size can be achieved by varying the CLTi parameter. The lowest swelling ratio, as an indication of the highest degree of crosslink, can be obtained by varying CLTe.

• 방사선산업학회지
• /
• 제5권2호
• /
• pp.159-164
• /
• 2011

A variety of natural polymers have been used as tissue engineering scaffolds, drug delivery system, and cosmetic materials due to their higher biocompatibility and water uptake. As a major component of extracellular matrix, hyaluronic acid consisting of D-glucuronic acid and N-acetylglucosamine has been popularly used as a hydrogel material. Even though it has good properties to be used in the tissue engineering and cosmetic industry, its higher viscosity has limited a potential use in a variety of applications; only low content should be applied in preparing above products. In the present study, we investigated the effect of electron beam irradiation on the properties of hyaluronic acid. Hyaluronic acid paste containing low contents of water changed to solution after electron beam irradiation ranging from 1 to 10 kGy, which didn't exhibit any alteration of surface properties and morphological change after freeze-drying. However, its viscosity was significantly decreased as absorbed dose increased, which was approximately one by hundred in comparison with the viscosity of original hyaluronic acid solution with same concentration. In addition, it can still interact with positive charged chitosan generating polyelectrolyte complex. Therefore, only viscosity was decreased after electron beam irradiation, whereas other properties of hyaluronic acid maintained. Consequently, these hyaluronic acids with lower viscosities can be used in a variety of applications in tissue engineering, drug delivery, and cosmetic industry.

• 통합자연과학논문집
• /
• 제12권4호
• /
• pp.116-121
• /
• 2019

This experiment is to evaluate the physical properties of the hydrogel lens with the addition of carbon-based nanomaterials, Graphene oxide and Carbon nanotube, and to confirm the improvement of strength. Hyaluronic acid, a hydrophilic substance, was used as an additive by using HEMA (2-hydroxyethyl methacrylate) and ethylene glycol dimethacrylate (EGDMA) as a base monomers. Graphene oxide and two types of Carbon nanotubes(Amide functionalized and Carboxilic acid functionalized) were added 0.1%, 0.3%, 0.5%, respectively, and the physical properties were analyzed by measuring water content, refractive index, breaking strength and SEM image. In the case of the sample added with each carbon nano material, the water content tended to increase for all three materials. The breaking strength tended to increase in Graphene oxide and Carbon nanotube; Carboxilic acid functionalized, but in the case of Carbon nanotube; amide fuctionalized, the breaking strength tended to decrease. However, Carbon nanotube; amide fuctionalized had the highest breaking strength among the three nano materials. Thus, the addition of certain carbon nanomaterials seems to be appropriate for improving the strength of hydrogel lenses.

• 폴리머
• /
• 제25권4호
• /
• pp.476-485
• /
• 2001

본 연구에서는 고분자 지지체를 만든 후 약물을 흡수시켜 방출 특성을 검토하는 기존의 방법에서 나타나는 초기 과다 방출이라는 단점을 보완하고 장기간에 걸친 약물방출이 가능한 고분자 지지체를 구축하기 위해 광반응 관능기를 갖는 히아루론산과 sodium alginate 유도체로 세포의 성장을 촉진하는 약물을 함입한 미립자를 만들고 이를 성형가공한 고분자 지지체를 제작하여 약물 방출 특성을 검토하였다. 이러한 방법으로 만들어진 지지체는 초기 방출이 억제되고 오랜 기간 동안 지속적으로 약물을 서서히 방출하였으며, 뿐만 아니라 천연고분자가 갖는 생체내 분해 특성으로 인하여 일정한 기간 동안 형태를 유지하며 지지체로 기능을 한 이후 분해되어 재생된 조직이 손상조직과 대체 가능하므로, 세포의 성장과 분화를 유도하는 손상조직 대체용 고분자 지지체 본연의 목적을 달성할 수 있을 것으로 기대된다.

• Tissue Engineering and Regenerative Medicine
• /
• 제15권6호
• /
• pp.761-769
• /
• 2018

BACKGROUND: Bioprinting has recently appeared as a powerful tool for building complex tissue and organ structures. However, the application of bioprinting to regenerative medicine has limitations, due to the restricted choices of bio-ink for cytocompatible cell encapsulation and the integrity of the fabricated structures. METHODS: In this study, we developed hybrid bio-inks based on acrylated hyaluronic acid (HA) for immobilizing bio-active peptides and tyramine-conjugated hyaluronic acids for fast gelation. RESULTS: Conventional acrylated HA-based hydrogels have a gelation time of more than 30 min, whereas hybrid bio-ink has been rapidly gelated within 200 s. Fibroblast cells cultured in this hybrid bio-ink up to 7 days showed >90% viability. As a guidance cue for stem cell differentiation, we immobilized four different bio-active peptides: BMP-7-derived peptides (BMP-7D) and osteopontin for osteogenesis, and substance-P (SP) and Ac-SDKP (SDKP) for angiogenesis. Mesenchymal stem cells cultured in these hybrid bio-inks showed the highest angiogenic and osteogenic activity cultured in bio-ink immobilized with a SP or BMP-7D peptide. This bio-ink was loaded in a three-dimensional (3D) bioprinting device showing reproducible printing features. CONCLUSION: We have developed bio-inks that combine biochemical and mechanical cues. Biochemical cues were able to regulate differentiation of cells, and mechanical cues enabled printing structuring. This multi-functional bio-ink can be used for complex tissue engineering and regenerative medicine.