In vivo evaluation of anticancer efficacy of drug loaded cockle shell-derived aragonite nanoparticles.

Doxorubicin (DOX) is an effective and commonly used anthracycline anticancer drug for the treatment of osteosarcoma (OS). However, its antitumor effect is hampered by the nonspecific distribution and significant adverse effects. Nanoparticles based drug delivery systems are promising approaches to maximize the anticancer efficacy while decrease the side effects. In this study, biogenic aragonite nanoparticles (ANPs) were developed from cockle shells and loaded with DOX. An orthotopic rat OS model was induced by UMR-106 cells tibia cavity injection. The anticancer efficacy study included five groups: normal control group, OS model group, free DOX group (2 mg/kg), DOX-ANPs 1 group (2 mg of equivalent DOX/kg) and DOX-ANPs 2 group (1.5 mg of equivalent DOX/kg). This study demonstrates that the DOX-ANPs treatment groups can significantly reduce the tumor volume and increase the surviving ratio as compared to the OS model group. In addition, these two DOX-ANPs groups showed less toxicity to the normal organs compared to the free DOX group. Furthermore, DOX-ANPs 2 group showed the similar anticancer efficacy as DOX-ANPs 1 group, which suggested that DOX loaded onto the ANPs may allow the reduction of chemotherapy doses. These results highlight the promising application of ANPs derived from cockle shells as an effective drug delivery system for a successful chemotherapy against OS. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1898-1907, 2019.

In vivo evaluation of a novel nanocomposite porous 3D scaffold in a rabbit model: histological analysis.

The healing of load-bearing segmental defects in long bones is a challenge due to the complex nature of the weight that affects the bone part and due to bending, shearing, axial, and torsional forces. An innovative porous 3D scaffolds implant of CaCO3 aragonite nanocomposite derived from cockle shell was advanced for substitute bone solely for load-bearing cases. The biomechanical characteristics of such materials were designed to withstand cortical bone strength. In promoting bone growth to the implant material, an ideal surface permeability was formed by means of freeze drying and by adding copolymers to the materials. The properties of coating and copolymers supplement were also assessed for bone-implant connection resolutions. To examine the properties of the material in advanced biological system, an experimental trial in an animal model was carried out. Critical sized defect of bone was created in rabbit's radial bone to assess the material for a load-bearing application with a short and extended period assessment with histological evaluation of the incorporated implanted material to the bone of the host. Trials in animal models proved that the material has the capability of enduring load-bearing conditions for long-term use devoid of breaking or generating stress that affects the host bone. Histological examination further confirmed the improved integration of the implanted materials to the host bone with profound bone development into and also above the implanted scaffold, which was attained with negligible reaction of the tissues to a foreign implanted material.

Full-thickness skin wound healing using autologous keratinocytes and dermal fibroblasts with fibrin: bilayered versus single-layered substitute.

Split-skin grafting (SSG) is the gold standard treatment for full-thickness skin defects. For certain patients, however, an extensive skin lesion resulted in inadequacies of the donor site. Tissue engineering offers an alternative approach by using a very small portion of an individual's skin to harvest cells for propagation and biomaterials to support the cells for implantation. The objective of this study was to determine the effectiveness of autologous bilayered tissue-engineered skin (BTES) and single-layer tissue-engineered skin composed of only keratinocytes (SLTES-K) or fibroblasts (SLTES-F) as alternatives for full-thickness wound healing in a sheep model. Full-thickness skin biopsies were harvested from adult sheep. Isolated fibroblasts were cultured using medium Ham's F12: Dulbecco modified Eagle medium supplemented with 10% fetal bovine serum, whereas the keratinocytes were cultured using Define Keratinocytes Serum Free Medium. The BTES, SLTES-K, and SLTES-F were constructed using autologous fibrin as a biomaterial. Eight full-thickness wounds were created on the dorsum of the body of the sheep. On 4 wounds, polyvinyl chloride rings were used as chambers to prevent cell migration at the edge. The wounds were observed at days 7, 14, and 21. After 3 weeks of implantation, the sheep were euthanized and the skins were harvested. The excised tissues were fixed in formalin for histological examination via hematoxylin-eosin, Masson trichrome, and elastin van Gieson staining. The results showed that BTES, SLTES-K, and SLTES-F promote wound healing in nonchambered and chambered wounds, and BTES demonstrated the best healing potential. In conclusion, BTES proved to be an effective tissue-engineered construct that can promote the healing of full-thickness skin lesions. With the support of further clinical trials, this procedure could be an alternative to SSG for patients with partial- and full-thickness burns.