Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, Defence Road, Off Raiwind Road, Lahore, 54000, Pakistan.
Institute of Biochemistry and Biotechnology, University of the Punjab, 54590 Lahore, Pakistan.
Colloids Surf B Biointerfaces. 2017 Dec 1;160:553-563. doi: 10.1016/j.colsurfb.2017.09.059. Epub 2017 Oct 4.
Alveolar bone loss is associated with infections and its augmentation is a pre-requisite for the success of dental implants. In present study, we aim to develop and evaluate novel freeze dried doxycycline loaded chitosan (CS)/hydroxyapatite (HA) spongy scaffolds where hydroxypropylmethyl cellulose (HPMC) was added as a crosslinker. Scaffolds displayed compressive strength of 14MPa/cm and 0.34 as elastic response. The interconnected pore diameter was 41-273μm, favorably provided the template supporting cells and transport. An overall 10% degradation was seen after 14day's studies at pH 7.4 in PBS. Doxycycline hyclate, a frequently used drug to counter oral infections, demonstrated an initial burst release (6-8h), followed by a sustain release profile for the remaining 64h. CS/HA/HPMC scaffolds were nontoxic and promoted pre-osteoblast cell viability as seen with live/dead calcein staining after 24h where scaffolds with 10% and 25% HPMC by weight of scaffold had more viable cells. Scaffolds with 10%, 20% and 25% HPMC by weight of scaffold showed efficient cellular adhesion as seen in scanning electron microscopy images (day 8) indicating that pre-osteoblast cells were able to adhere well on the surface and into the porous structure via cytoplasmic extensions. Hoechst 33258 nuclear staining at day 2 and 8 indicated cell proliferation which was further supported byMTT assay at day 2, 4 and 8. Although all scaffolds supported pre-osteoblast cell viability, alkaline phosphatase (ALP) staining demonstrated that upon induction, differentiation was pronounced in case of scaffolds with 10% HMPC scaffolds. Conclusively, these materials having all the required mechanical and biological properties are potential candidates for alveolar bone regeneration.
牙槽骨丧失与感染有关，其增加是牙种植体成功的前提。在本研究中，我们旨在开发和评估新型冻干盐酸多西环素负载壳聚糖（CS）/羟基磷灰石（HA）海绵状支架，其中添加羟丙基甲基纤维素（HPMC）作为交联剂。支架的压缩强度为 14MPa/cm，弹性响应为 0.34。相互连通的孔径为 41-273μm，有利于细胞和运输的模板支撑。在 pH7.4 的 PBS 中，14 天后的研究中观察到总降解率为 10%。盐酸多西环素是一种常用于治疗口腔感染的药物，在最初的 6-8 小时内表现出快速释放（初始突释），随后在剩余的 64 小时内呈现持续释放的特征。CS/HA/HPMC 支架无毒性，并通过 24 小时后 calcein 染色的活/死细胞染色观察到促进前成骨细胞活力，其中支架重量的 10%和 25%的 HPMC 具有更多的存活细胞。支架重量的 10%、20%和 25%的 HPMC 具有高效的细胞粘附性，如扫描电子显微镜图像（第 8 天）所示，表明前成骨细胞能够通过细胞质延伸很好地粘附在表面和多孔结构上。第 2 天和第 8 天的 Hoechst 33258 核染色表明细胞增殖，在第 2、4 和 8 天的 MTT 测定中进一步得到支持。虽然所有支架都支持前成骨细胞的活力，但碱性磷酸酶（ALP）染色表明，在诱导的情况下，10% HMPC 支架的分化更为明显。总之，这些具有所有必需的机械和生物学特性的材料是牙槽骨再生的潜在候选材料。
