• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.229-231
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• 2012

Hyaluronic acid(HA)는 보습성, 생체적합성, 고점도성의 특징이 있는 수용성 다당류로 분자량에 따라 보습, 탄성, 점성 등이 달라진다. 또한 피부의 침투성 또한 분자량에 가장 큰 영향을 받는다. 본 연구에서는 HA를 저분자화하여 10만Da-1천Da의 저분자 히알론론산을 제조하고 이를 아세틸화하여 항주름 및 항염활성을 측정한 결과 분자량이 낮은 분자량일 수록 우수한 항주름 및 항염활성을 나타내었으며 아셀틸화한 것이 하지 않은 것에 비하여 높은 항주름 및 항염활성을 나타 내었다.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.803-808
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• 2010

Poly-${\gamma}$-glutamic acid (${\gamma}$-PGA) is a natural edible polypeptide in which glutamate is polymerized via ${\gamma}$-amide linkages. First, we assessed the eye irritancy potential of ${\gamma}$-PGA in rabbits. Additionally, we studied the effects of ${\gamma}$-PGA on corneal wound healing, due to the anti-inflammatory properties and water retaining abilities of ${\gamma}$-PGA. In this study, the effects of ${\gamma}$-PGA on corneal wound healing after an alkali burn were evaluated. Thirty eyes wounded by alkali burning in 30 white rabbits were divided into three groups: group A was treated with 0.1% 5,000 kDa ${\gamma}$-PGA for 2 days; group B was treated with 0.1% hyaluronic acid; and group C was not treated, as a control. The area of corneal epithelial defect was examined at 12, 24, 30, 36, 42, and 48 h after corneal alkali wounding to determine initial wound healing. We found that ${\gamma}$-PGA promoted corneal wound healing, compared with controls, and showed similar effects to hyaluronic acid. These results indicate that ${\gamma}$-PGA stimulates corneal wound healing by an anti-inflammatory effect and enhancing cell migration and cell proliferation. ${\gamma}$-PGA is a promising biomaterial that may be a substitute for hyaluronic acid in corneal wound healing treatment.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.158-165
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• 2010

Purpose: The objective of the present study was to histologically evaluate durability and bone regeneration capacity of new synthetic membranes in comparison to clinically available collagen membrane. Material and methods: To the skulls of 12 rabbits, we created 4 bone defects of 6 mm in diameter on each of them. Each of defects were covered with at least one of 5 membranes; No membrane, Collagen ($Ossix^{TM}$), PLGA, HA-coated-PLGA and HA-PLGA/PLGA. After 4, 8, 12 weeks, we cut the skulls and dyed with H-E. And then, the histologic observation was done. Results: In current study, the control group which did not use the membrane showed bone regeneration at 12 weeks and covered the bone defect partially. New bones were formed through the underneath of endocranium, and the upper defect was filled with connective tissues and fats. Collagen membrane ($Ossix^{TM}$) showed new bones after 4 weeks, and they were formed through the membrane which maintained until 12 weeks. PLGA, HA-coated-PLGA, HA-PLGA/PLGA showed bone regeneration after 4 weeks and after 8 weeks, they mostly filled defects. At 12 weeks, we could find new bones and previous bones almost look alike and also, they united well. Membranes were unnoticeable after 4 weeks and were absorbed. Conclusion: Bone formation and maturation of PLGA, HA-coated-PLGA and HA-PLGA/PLGA were faster than the control group. They showed no difference on the application of HA and after 4 weeks, they were absorbed.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.175-180
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• 2020

Purpose: In this study, we used ultrasonography to monitor the use of hyaluronic acid (HA) as a filler in the face for esthetic reasons. We monitored changes in the filler shape, distribution, and relationship with adjacent anatomical structures over a 180-day period. Materials and Methods: Two patients each received an ultrasound-guided injection of HA, with different products and application sites for each patient. In 1 patient, the injection was administered in the angle of the mandible, while in the other, it was administered in the zygomatic region. The injection sites were monitored via ultrasonography at 24 hours, 30 days, and 180 days, at which times the imaging characteristics of the filler were observed. All injections were performed by the same professional, as were the ultrasound exams, which were conducted using the same equipment. Results: In both cases, the HA fillers were visualized using ultrasound at all time points. Some differences were observed between the cases in the images and the distribution of the pockets of filler. In 1 case, the filler appeared as a dark hypoechoic region with well-defined contours, and the material was observed to have moved posteriorly by the 180-day mark. In the other case, the material appeared hyperechoic relative to the previous case and presented no noticeable changes in its anteroposterior distribution over time. Conclusion: Based on these 2 cases, ultrasonography can be a complementary tool used to monitor facial fillers over the long term, allowing for the dynamic observation of different fillers.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.399-406
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• 2015

In this study, we developed a composite filler comprising cross-linked hyaluronic acid (HA) and human collagen (COL) derived from the human umbilical cord with the aim of improving its biocompatibility and longevity compared with commercially available fillers. After HA/COL composite fillers were made in two different ratios (10:1 and 5:1), the physical properties of the fillers were evaluated. The interior morphologies and in vivo weight change of these hydrogels were also characterized at 1-16 weeks after injection into mice. To evaluate their biocompatibility and durability in vivo, we injected the composite fillers into nude mice subcutaneously. The variations of injected gel weight were measured and compared with the commercial dermal fillers (Restylane and TheraFill). The composites showed improved or similar physical properties (complex viscosity of 19-22 × 10⁵ cP, and injection force of 10-12 N) over the commercial dermal fillers. Sixteen weeks following the injection, the ratio of remaining composite filler weight to initial weight (75.5 ± 16.9%; 10:1) was shown to be greater than that of the commercial fillers (43.2 ± 8.1%, Restylane; 12.3 ± 5.3%, TheraFill). In addition, immunohistochemical analysis with angiogenesis-related markers such as isolectin and vWF revealed newly formed blood vessels and cellular influx into the composite filler, which were not observed in the other fillers. These results clearly suggest that the HA/COL composite filler is a superior candidate for soft tissue reconstruction. The filler we developed may be a suitable candidate as an injectable dermal filler for tissue augmentation in humans.

• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.596-603
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• 2009

This study aimed to examine the influence of adding an oxygen vector, n-dodecane, on hyaluronic acid (HA) production by batch culture of Streptococcus zooepidemicus. Owing to the high viscosity of culture broth, microbial HA production during 8-16 h was limited by the oxygen transfer coefficient $K_La$, which could be enhanced by adding n-dodecane. With the addition of n-dodecane to the culture medium to a final concentration of 5% (v/v), the average value of $K_La$ during 8-16 h was increased to $36{\pm}2h^{-1}$, which was 3.6 times that of the control without n-dodecane addition. With the increased $K_La$ and dissolved oxygen (DO) by adding 5% (v/v) of n-dodecane, a 30% increase of HA production was observed compared with the control. Furthermore, the comparison of the oxygen mass transfer in the absence and presence of n-dodecane was conducted with two proposed mathematical models. The use of n-dodecane as an oxygen vector, as described in this paper, provides an efficient alternative for the optimization of other aerobic biopolymer productions, where $K_La$ is usually a limiting factor.

• Membrane Journal
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• v.15 no.4
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• pp.281-288
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with lactide, the ester dimer of polylactide, with good biodegradability to produce biocompatible materials applicable to drug delivery system. By freeze drying method, HA and lactide were crosslinked with crosslinking agent, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. Degree of lactide and EDC reaction was determined by the analysis of nuclear magnetic resonance (NMR) spectroscopy. The degree of lactide and EDC reaction increased and swelling ratio decreased as the mole ratio of lactide to HA or crosslinking agent concentration increased or reaction temperature decreased. The drug release experiment result from membranes having different degree of lactide reaction showed that drug release rate reduced in proportion to the degree of lactide reaction. The drug release experiment result from drugs having different hyrodphobicity showed that the more hydrophobic drug was released more slowly.

• Journal of Periodontal and Implant Science
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• v.51 no.1
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• pp.63-74
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• 2021

Purpose: This study investigated the effects of hyaluronic acid (HA) on peri-implant clinical variables and crevicular concentrations of the proinflammatory biomarkers interleukin (IL)-1β and tumor necrosis factor (TNF)-α in patients with peri-implantitis. Methods: A randomized controlled trial was conducted in peri-implantitis patients. Patients were randomized to receive a 0.8% HA gel (test group), an excipient-based gel (control group 1), or no gel (control group 2). Clinical periodontal variables and marginal bone loss after 0, 45, and 90 days of treatment were assessed. IL-1β and TNF-α levels in crevicular fluid were measured by enzyme-linked immunosorbent assays at baseline and after 45 days of treatment. Clustering analysis was performed, considering the possibility of multiple implants in a single patient. Results: Sixty-one patients with 100 dental implants were assigned to the test group, control group 1, or control group 2. Probing pocket depth (PPD) was significantly lower in the test group than in both control groups at 45 days (control 1: 95% CI, -1.66, -0.40 mm; control 2: 95% CI, -1.07, -0.01 mm) and 90 days (control 1: 95% CI, -1.72, -0.54 mm; control 2: 95% CI, -1.13, -0.15 mm). There was a trend towards less bleeding on probing in the test group than in control group 2 at 90 days (P=0.07). Implants with a PPD ≥5 mm showed higher levels of IL-1β in the control group 2 at 45 days than in the test group (P=0.04). Conclusions: This study demonstrates for the first time that the topical application of a HA gel in the peri-implant pocket and around implants with peri-implantitis may reduce inflammation and crevicular fluid IL-1β levels.

• Clinical Pain
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• v.18 no.1
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• pp.16-23
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• 2019

Objective: To evaluate the effectiveness of dynamic balance exercise after intra-articular injection of hyaluronic acid (HA) therapy in elderly patients with unilateral knee osteoarthritis. Method: 30 patients with unilateral knee osteoarthritis were enrolled in this study. The patients were randomly divided into two groups: dynamic balance exercise after HA injection group (group A) and only HA injection group (group B). Both groups administered intra-articular HA injection and group A patients continued 20-session exercises for 4 weeks. The assessments were measured before injection and 4 weeks after treatment using the visual analog scale (VAS) for pain, the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) for physical function, Berg balance scale (BBS), and computerized dynamic posturography using SMART Balance Master system for balance function. Results: In both groups, significant improvements in VAS, WOMAC and balance function were observed. Compared between groups, group A showed significant improvements compared to group B in WOMAC and balance function. Conclusion: It is suggested that dynamic balance exercise may result in improved balance function and physical function in elderly patients with unilateral knee osteoarthritis.

• Biomolecules & Therapeutics
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• v.32 no.5
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• pp.635-639
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• 2024

Skin aging results from complex interactions of intrinsic and extrinsic factors, leading to structural and biochemical changes such as wrinkles and dryness. Ultraviolet (UV) irradiation leads to the degradation of hyaluronic acid (HA) in the skin, and the fragmented HA contributes to inflammation. This study revealed that the synergistic combination of carnosine and retinol (ROL) increases HA production in normal human epidermal keratinocytes (NHEKs) by upregulating hyaluronan synthase 2 (HAS2) gene transcription. Simultaneously, the combined treatment of carnosine and ROL significantly attenuates UVB-induced prostaglandin E₂ (PGE₂) synthesis in NHEKs. A significant correlation exists between the increase of HA synthesis and the inhibition of PGE₂ production. This study suggests that combined treatment of carnosine and ROL can improve skin aging phenotypes associated with UVB irradiation.