Are different crystallinity-index-calculating methods of hydroxyapatite efficient and consistent?

Sa, Yue; Guo, Yaru; Feng, Xiaowei; Wang, Man; Li, Ping; Gao, Yixue; Xu, Yang; Jiang, Tao

doi:10.1039/c7nj00803a

Cited by 92 publications

(68 citation statements)

References 39 publications

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“…The crystallinity index (CI) is a measure of the perfection and degree of ordering in a sample. It correlates linearly with NHAp crystal size and perfection in the caxis direction, and has obvious influences on hardness and density of the material [2,32,33]. CI is calculated (Table 1) from both FTIR (height method) and XRD (height method) according to the method and formulae used by the researchers [32,[34][35][36].…”

Section: Crystallinity Index (Ci)mentioning

confidence: 99%

“…High substitution of CO 3 2 -in NHAp/PVP reduces its crystallinity considerably [37]. NHAp with reduced crystallinity has high solubility and protein absorption capacity [33].…”

Section: Crystallinity Index (Ci)mentioning

confidence: 99%

“…The present CI values are compared with different samples such as HAp prepared by precipitation method ((CI)FTIR = 3.67 to 6.07; (CI)XRD = 0 to 1.18) [32], fresh bone ((CI) FTIR = 2.8) [32], marine apatites ((CI) FTIR = 3.0 to 3.6) [35], HAp with different temperatures ((CI)FTIR = 4.63 to 7.80) [33] and modern bones ((CI)FTIR = 2.69 to 3.37) [34]. The present (CI)FTIR values are matched with CI values of fresh bone, while present (CI)XRD values are higher than HAp prepared by precipitation method [32].…”

Section: Crystallinity Index (Ci)mentioning

confidence: 99%

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Hydroxyapatite for bone related applications derived from sea shell waste by simpleprecipitation method

Kumar

Dhanaraj

Vimalathithan³

et al. 2020

Journal of Asian Ceramic Societies

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The nano-hydroxyapatite (NHAp), NHAp/PEG and NHAp/PVP have been derived from Clam shell by precipitation method. The presence of characteristic FTIR peaks and XRD planes indicates the formation of NHAp. Surface morphology of NHAp, NHAp/PEG and NHAp/PVP appeared to be flake, majorly hexagonal and rod clusters like structure, respectively. Sizes of the NHAp are in nanometer scale and size of NHAp/PVP is the lowest. The poor crystalline nature and high carbonate content presence in NHAp/PVP are assessed through crystallinity index, C/P ratio and CHNS analysis. EDX analysis shows the presence of HAp composition in NHAp. The calculated structural parameters expose that the NHAp/PVP shows favorable mechanical property. Good antibacterial activity is observed in NHAp/PVP against two bacteria strains. Hemolysis study also indicates that NHAp/PVP is non-hemolytic. Formation of complete apatite is found when NHAp/PVP immersed in SBF for 14 days. Thus, the NHAp/PVP derived from Clam shell may be useful for bone-related applications. ARTICLE HISTORY

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Section: Crystallinity Index (Ci)mentioning

confidence: 99%

“…High substitution of CO 3 2 -in NHAp/PVP reduces its crystallinity considerably [37]. NHAp with reduced crystallinity has high solubility and protein absorption capacity [33].…”

Section: Crystallinity Index (Ci)mentioning

confidence: 99%

Section: Crystallinity Index (Ci)mentioning

confidence: 99%

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Hydroxyapatite for bone related applications derived from sea shell waste by simpleprecipitation method

Kumar

Dhanaraj

Vimalathithan³

et al. 2020

Journal of Asian Ceramic Societies

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“…Os resultados de DRX não apresentaram nenhuma alteração estrutural e comprovaram a presença das duas fases (CHI e HA) nos compósitos. A partir dos resultados de DRX obtevese o índice de cristalinidade (IC) das amostras (Tabela II), onde foi observado que todas apresentaram um valor de IC baixo, indicando baixa cristalinidade da HA [18]. O IC dos compósitos com quitosana de média massa molecular (M-CHI50/HA50 e M-CHI20/HA80) foi um pouco maior do que aqueles preparados com quitosana de baixa massa molecular ((L-CHI50/HA50 e L-CHI20/HA80), o que sugeriu que os biomateriais desenvolvidos possuíram uma característica amorfa predominante; isso pode ser devido ao fato de não terem sido sinterizados, o que pode favorecer uma maior biodegradabilidade.…”

Section: Resultsunclassified

“…Para o cálculo do índice de cristalinidade (IC) das amostras, utilizaram-se os padrões de DRX, conforme a Eq. D [18], onde β 002 representa a largura à meia altura da reflexão do plano (002): IC = (0.24/b 002 ) 3 (D)…”

Section: Methodsunclassified

Produção, caracterização e avaliação in vitro de partículas de quitosana e hidroxiapatita para substituição óssea

et al. 2019

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Resumo Objetivou-se desenvolver, caracterizar e avaliar in vitro biomateriais compósitos de quitosana com hidroxiapatita (CHI/HA) para atuarem como substitutos ósseos. As quitosanas de baixa (L-CHI) e média (M-CHI) massa molecular foram previamente caracterizadas por gravimetria, viscosimetria e espectrofotometria ultravioleta. Os compósitos de CHI/HA foram produzidos por precipitação in situ, seguida de centrifugação (micropartículas) ou spray drying (nanopartículas), e caracterizados por microscopia eletrônica de varredura, espectroscopia de infravermelho com transformada de Fourier e difração de raios X. A citotoxicidade in vitro foi determinada por teste de viabilidade celular. L-CHI e M-CHI apresentaram, respectivamente, 15,7% e 16,4% de umidade, 0,51% e 0,18% de cinzas, 79,5% e 77,7% de grau de desacetilação e 4,18.104 e 17,3.104 de massa molecular média viscosimétrica. Os compósitos exibiram grupos característicos dos materiais de origem e escassa citotoxicidade. Concluiu-se que as técnicas foram eficazes para produção dos biomateriais, com características físico-químicas e biológicas adequadas para utilização nas terapias ósseas.

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Enzymatic hydrolysis of thermally pre‐treated chitin and antimicrobial activity of N,N′‐diacetylchitobiose

Abidin

Kourmentza

Karatzas

et al. 2019

J of Chemical Tech & Biotech

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BACKGROUND: N,N ′ -diacetylchitobiose (GlcNAc 2 ) is known to be highly functional and offers a wide range of applications, especially as an antimicrobial agent. In this study, a thermal pre-treatment process using steam under pressure in an autoclave was employed to facilitate subsequent enzymatic hydrolysis of chitin with chitinase from Streptomyces griseus. RESULTS:Pre-treatment of chitin with 0.05 mol L −1 sodium acetate buffer (pH = 6.0) at 121 ∘ C for 60 min, followed by enzymatic hydrolysis involving 24 h incubation, were found to be the best conditions for producing GlcNAc 2 . The GlcNAc 2 thus obtained was tested regarding its antimicrobial activity against Gram-negative and Gram-positive strains and showed minimum inhibitory concentrations at 5 and 10% (w/v) against Escherichia coli K-12 and Listeria monocytogenes 10403S, respectively. CONCLUSIONS: The extent of swelling and crystallite size of chitin increased with pre-treatment residence time, and enhanced the rate of subsequent hydrolysis using chitinase. GlcNAc H+GlcNAc2 H+ GlcNAc2 Na+ Figure 4. LC-MS spectrum of hydrolysate formed from PC-60 after hydrolysis at 40 ∘ C for 24 h by chitinase from Streptomyces griseus.

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Are different crystallinity-index-calculating methods of hydroxyapatite efficient and consistent?

Abstract: Different CI-calculating methods of XRD, FTIR and Raman techniques showed high efficiency and consistency.

Cited by 92 publications

References 39 publications

Hydroxyapatite for bone related applications derived from sea shell waste by simpleprecipitation method

Hydroxyapatite for bone related applications derived from sea shell waste by simpleprecipitation method

Produção, caracterização e avaliação in vitro de partículas de quitosana e hidroxiapatita para substituição óssea

Enzymatic hydrolysis of thermally pre‐treated chitin and antimicrobial activity of N,N′‐diacetylchitobiose

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