• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.220-228
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• 2018

In this study, we found a simple surface biofunctionalization of biphasic calcium phosphate (BCP) based on the high affinity between alendronate and the calcium ions of BCP, and the strong interaction between heparin and bone morphogenic protein-2 (BMP-2). The biofunctionalized BCP did not be precipitated well and display a remarkable enhancement of osteogenic activity of human adipose-derived stem cells by showing increased alkaline phosphatase (ALP), calcium deposition and osteogenic-related genes (i.e., Runx-2, ALP, osteocalcin, and osteopontin), and bone regeneration in the calvarial defect model. Therefore, this simple surface technique can be used to easily functionalize various calcium phosphates.

• Journal of Ceramic Processing Research
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• 제20권6호
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• pp.655-659
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• 2019

Calcium phosphates such as HA (hydroxyapatite), β-TCP (tricalcium phosphate) and biphasic HA/β-TCP, were synthesized by wet chemical precipitation in aqueous solution combined with ball milling process. Nanosize powders of the calcium phosphates were synthesized using Ca(OH)2 and H3PO4. The effects of initial precursor Ca/P ratio (1.30, 1.50 and 1.67), ball milling process and post heat-treatment on the phase evolution behavior of the powders were investigated. The phase of resulting powder was controllable by adjusting the initial Ca/P ratio. HA was the only phase for as-prepared powders in both cases of Ca/P ratios of 1.50 and 1.67. The single HA phase without any noticeable second phase was obtained for the initial Ca/P ratio of 1.67 in the overall heat-treatment range. Pure β-TCP and biphasic calcium phosphate (HA/β-TCP) were synthesized from precursor solutions having Ca/P molar ratios of 1.30 and 1.50, respectively, after having been heat-treated above 700 ℃. The β-TCP phase has appeared on the pre-existing DCPD (dicalcium phosphate dihydrate) and/or HA phase. Dense ceramics having translucency were obtained at a considerably lower sintering temperature. The modified process offered a fast, convenient and economical route for the synthesis of calcium phosphates.

• 한국결정성장학회지
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• 제21권4호
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• pp.169-174
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• 2011

합성된 biphasic calcium phosphate(BCP) 분말의 나노크기 생분해성 거동은 X-선 회절 분석방법, 격자 매개변수 및 전계방출형 주사전자현미경을 통해 특성평가 하였다. BCP 분발은 공침반응 및 하소과정을 통해 합성하였고, 합성된 분발은 행크 용액 (pH = 7.4, $36.5^{\circ}C$)을 이용하여 3주 동안 in vitro 시험 하였다 분해 시험(in vitro) 후, BCP 단위포의 매개변수는 a 및 c축의 불규칙한 변화와 비슷한 격자 왜곡 및 팽창 거동을 보였다.

• 한국결정성장학회지
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• 제30권4호
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• pp.143-149
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• 2020

전복패각을 Ca원으로 이용하여 바이오 소재로 중요한 인산칼슘(calcium phosphates)들을 침전법을 통해 합성하였다. 전복패각에서 유래한 수산화칼슘(Ca(OH)₂)을 칼슘 공급원(전구체)으로 사용하였다. 수용액상에서 수산화칼슘과 인산(H₃PO₄)을 반응시켜 침전반응을 유도하여 인산칼슘화합물로의 합성을 유도하였다. 초기 전구체 Ca/P 비율을 1.50, 1.59 및 1.67로 조절하였으며 이 조성변화와 침전물에 대한 열처리가 분말 및 소결체의 물성에 미치는 영향에 대해 조사하였다. 초기 전구체 Ca/P 비율을 조절함으로써 소결체 상합성의 조절이 가능하였고, 1150℃에서 소결한 소결체에서(hydroxyapatite(HAp), β-tricalcium phosphate(β-TCP) 및 HAp와 β-TCP가 혼합된 2상 인산칼슘(BCP, HA/β-TCP))들이 합성되었다. 이러한 결과는 저비용, 고가용성을 가지는 경제적인 출발물질로부터 고부가가치 인산칼슘을 합성할 수 있는 가능성을 보여주었다.

• 한국결정성장학회지
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• 제20권2호
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• pp.93-100
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• 2010

X-선 회절 분석방법을 통해 biphasic calcium phosphate(BCP) 분말의 Ca/P 몰 비율을 확인하고 특성을 평가하였다. 다양한 화학 양론적인 Ca/P 몰 비율을 가지는 BCP 분말은 공침반응 및 하소과정을 통해 합성하였다. 1.5에서 1.67의 Ca/P 몰 비율을 가지는 분말의 조성은 초기 출발물질의 Ca/P 몰 비율, pH 10에서의 공침 과정 및$900^{\circ}C$ 열처리에 의해 정해졌다. 화학 양론적 Ca/P 몰 비율을 가지는 BCP 분말의 구조, 형상 및 화학적 특성평가는 XRD의 상-정량 확인 분석을 바탕으로 주사전자현미경 및 유도 결합 플라즈마 분광분석기와 함께 수행 하였다. BCP 분말의 용해도는 $36.5^{\circ}C$ 및 pH 7.4 의 phosphate buffer solution(PBS)에서 특성평가 하였다.

• 한국결정성장학회지
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• 제20권5호
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• pp.243-248
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• 2010

Si-BCP(si-substituted biphasic calcium phosphate)를 제조하기 위하여 $Ca(NO_3)_2{\cdot}4H_2O$, $(NH_4)_2HPO_4$, $Si(OC_2H_5)_4$을 출발 물질로 공침법(co-precipitation process)을 이용하여 합성하였다. 합성된 분말의 HAp/${\beta}$-TCP 결정상 비율 및 Si-P 치환 거동은 X-선 회절 상 분석을 이용하여 측정하였고, silicon ion 첨가 시 나타나는 BCP의 화학적 결합거동을 측정하기 위하여 FT-IR를 사용하여 분석하였다. 또한 Si-BCP 분말의 in-vitro 생분해거동 및 생체활성도를 측정하기 위하여 제조된 분말을 SBF(simulated body fluid) solution에 침적시킨 뒤 분말의 형상과 구성 성분은 SEM과 EDS를 통하여 확인하였다.

• 한국결정성장학회지
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• 제29권5호
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• pp.203-207
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• 2019

인산칼슘(hydroxyapatite(HAp), ${\beta}$-tricalcium phosphate(${\beta}$-TCP) 및 HAp와 ${\beta}$-TCP가 혼합된 2상 인산칼슘(BCP, HA/${\beta}$-TCP))들을 수열합성법을 통해 합성하였다. 여러 수열합성 조건(최고온도 $150^{\circ}C$ 및 pH 12 이하)에서 수산화칼슘($Ca(OH)_2$) 수용액과 인산($H_3PO_4$) 용액을 반응시켜 얻은 침전물을 수열합성에 이용하였다. 초기 전구체 Ca/P 비율을 1.30, 1.50 및 1.67로 조절하였으며 이 조성비와 합성 후 열처리가 분말 및 소결체의 상합성에 미치는 영향에 대해 조사하였다. 초기 전구체 Ca/P 비율을 조절함으로써 분말 및 소결체의 상의 조절이 가능하였다. Ca/P 비율이 1.67일 경우 모든 열처리 온도에서 분말 및 소결체 모두에서 HAp 단일 상이 합성되었다. Ca/P 비율이 1.30과 1.50에서 $900^{\circ}C$ 이상 열처리 할 경우 각각 순수한 ${\beta}$-TCP와 BCP(HAp/${\beta}$-TCP)가 합성되었다. 반응성 높은 미세한 분말을 이용하여 소결함으로써 미세한 입경을 가지며 투광성을 가지는 소결체들을 저온에서 얻을 수 있었다.

• 한국결정성장학회지
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• 제20권5호
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• pp.237-242
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• 2010

Mg-BCP(Mg Substituted BCP)를 제조하기 위하여 $Ca(NO_3)_2{\cdot}4H_2O$(Katayama chemical, Japan)과 $(NH_4)_2{\cdot}HPO_4$ (Junsei chemical, Japan), $Mg(NO_3)_2{\cdot}6H_2O$(Junsei chemical, Japan)를 출발물질로 공침법(co-precipitation process)을 이용하여 합성하였다. 제조된 분말의 마그네슘의 첨가에 따른 분말의 분광학적 특성은 FT-IR(MAGNA-IR 560, Nicolet)을 통하여 분석하였으며, SEM(S-4200, Hitachi)을 통하여 미세구조를 분석하였다. XRD 회절피크의 면적적분강도를 Integral Analysis (Rigaku, Japan)를 이용하여 HAp와 ${\beta}$-TCP의 비율을 확인하였다. 1.0 wt% 마그네슘이 첨가된 BCP 샘플의 경우 Hank's solution에서의 2주 침적 후 표면에 침상의 HAp로 추정되는 결정이 성장하였다. 이러한 미세구조의 변화는 생활성을 가지는 마그네슘의 첨가가 BCP 조직 내에서 표면의 활성을 증가시켜 결정의 성장을 촉진시킨 것으로 판단된다.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.163-170
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• 2008

Purpose: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate($\beta$-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. Materials and Methods: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/$\beta$-TCP ratio of 7:3 and particle size of $0.5{\sim}1.0\;mm$ was used as the test group and bovine bone with $0.25{\sim}1.0\;mm$ particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. Results: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. Conclusion: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.

• Journal of Periodontal and Implant Science
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• 제42권4호
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• pp.127-135
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• 2012

Purpose: The aim of this study was to compare the clinical outcome of open flap debridement (OFD) with a biphasic calcium phosphate (BCP) graft to that of OFD without BCP graft for the treatment of intrabony periodontal defects (IBDs). Methods: The study included 25 subjects that had at least one intrabony defect of 2- or 3-wall morphology and an intrabony component ${\geq}4$ mm as detected radiographically. Subjects were randomly assigned to treatment with (BCP group, n=14) or without BCP (OFD group, n=11). Clinical parameters were recorded at baseline and 6 months after surgery and included the plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC). A stringent plaque control regimen was enforced for all of the patients during the 6-month observation period. Results: In all of the treatment groups, significant PD reductions and CAL gains occurred during the study period (P<0.01). At 6 months, patients in the BCP group exhibited a mean PD reduction of $3.7{\pm}1.2$ mm and a mean CAL gain of $3.0{\pm}1.1$ mm compared to the baseline. Corresponding values for the patients treated with OFD were $2.5{\pm}0.8$ mm and $1.4{\pm}1.0$ mm, respectively. Compared to OFD group, the additional CAL gain was significantly greater in the patients in BCP group (P=0.028). The additional PD reduction was significant for the BCP group (P=0.048). The REC showed a significant increase in both groups, and the amount of recession was significantly smaller in the BCP group than OFD group (P=0.023). In radiographic evaluation, the height of the bone fill in the BCP group was significantly greater than OFD group. Conclusions: The clinical benefits of BCP found in this study indicate that BCP may be an appropriate alternative to conventional graft materials.