In vivo hydroxyapatite scaffold performance in infected bone defects

Abstract

Critically sized bone defects are often compounded by infectious complications. The standard of care consists of bone autografts with systemic antibiotics. These injuries and treatments lead to donor site morbidity, antibiotic resistant strains of bacteria, and often end stage amputation. This study proposes an alternative to the autograft using a porous, hydroxyapatite (HA) scaffold evaluated with and without infection and antibiotics. Twenty‐four New Zealand white rabbits received either our HA scaffold or a pulverized autograft (PBA) within a surgically created critical‐sized defect in the femur. The two grafts were evaluated in either septic or aseptic defects and with or without antibiotic treatment. The HA scaffolds were characterized with micro computed tomography. Post‐euthanasia, micro computed tomography, histology, and white blood cells component analysis were completed. The HA had significantly greater (p < .001) mineralization to total volume than the PBA groups with 27.56% and 14.88%, respectively, and the septic HA groups were significantly greater than the aseptic groups both with and without antibiotics (p = .016). The bone quality denoted by bone mineral density was also significantly greater (p < .001) in the HA groups (67.01 ± 0.38 mgHA/cm3) than the PBA groups (64.66 ± 0.85 mgHA/cm3). The HA scaffold is a viable alternative to the bone autograft in defects with and without infection as shown by the quality and quantity of bone.

In Vitro Re-Hardening of Bleached Enamel Using Mineralizing Pastes: Toward Preventing Bacterial Colonization

“…Hydroxyapatite and hydroxyapatite-based composites are widely used in dentistry and orthopedics [27][28][29]. They have also confirmed good performances in infection scenarios [30,31].…”

Моделирование Движения Питательных Веществ В Пористой Структуре Биокаркаса На Основе Гидроксиапатита Кальция

“…Поскольку клетки, расположенные во внутренней части каркаса, получают питательные вещества только через диффузию из окружающей среды в статической культуре, многие исследователи [19] предполагают, что высокая плотность клеток на внешней стороне каркаса может истощить запас питательных веществ, прежде чем эти питательные Подставляя выражение для CD из уравнения (17) и используя определение Re из уравнения (13), получаем Объединение уравнений (8), (9), (10), (11) и (14) дает где: ζ -постоянная, которая принимается равной X*(2ε2 -n λ)/α, чтобы поддерживать согласованность с уравнением (11), Ci -коэффициенты, которые существенно зависят от геометрии поры.…”

Desenvolvimento de matrizes de colágeno/nanohidroxiapatita contendo extratos vegetais para regeneração óssea

“…A hidroxiapatita é uma biocerâmica que, assim como o colágeno, pode estimular e orientar a formação de tecido ósseo. Em sua forma nanoparticulada ainda possibilita melhor sorção de proteínas e adesão celular, o que acelera a reparação óssea (Pearson et al, 2019).…”

“…A hidroxiapatita se destaca em relação a outras biocerâmica por sua biocompatibilidade, já que é o componente majoritário da parte inorgânica do osso, e por sua biodegradabilidade, já que é sujeita a ação de osteoclastos, podendo ser absorvida pelo organismo (Alt et al, 2016). (Hench, 2013;Alt et al, 2016;Bezerra et al, 2017;Yang et al, 2018;Pearson et al, 2019).…”

“…Figura 40: Fotografia digital da determinação da CIM da linhagem de S. aureus, sendo: J) extrato de casca de jabuticaba; R) extrato de casca de romã; P) extrato semente de uva; C+) controle positivo; C-) controle negativo Já que os extratos atuam como agente reticulante do colágeno, estes estão ligados física ou quimicamente à estrutura polimérica, reduzindo sua difusibilidade no meio e reduzindo assim, sua ação antimicrobiana (He et al, 2011;Vidal et al, 2016 (Shanthi et al, 2009;Bezerra et al, 2017;Pearson et al, 2019). Também é observado que com o aumento na concentração da nanohidroxiapatita, ocorre o aumento da viabilidade celular chegando próxima a 160% em períodos de 24 e 48h, indicando que a nanohidroxiapatita sintetizada apresenta…”