Safety and efficacy of hydroxyapatite scaffold in the prevention of jaw osteonecrosis in vivo.

Two scaffolds of chitosan/sodium alginate/hydroxyapatite (Ch/NaAlg/Hap) 1:1:0.2 and 1:1:0.6 were evaluated in the prevention of bisphosphonate-induced jaw osteonecrosis. Two groups of rats (n = 24, according to the euthanasia time: 15 or 30 days after the last Zoledronic acid (ZA) administration) were subdivided in four subgroups (n = 6): I - Control (saline + teeth extraction); II - ZA 0.6 mg/kg + teeth extraction; III - ZA + teeth extraction + scaffold 1:1:0.2; IV - ZA + teeth extraction + scaffold 1:1:0.6. Jaws were evaluated histologically and blood was evaluated for hematological and biochemical parameters. Histopathology showed significant osteonecrosis in AZ group. The scaffold's implantation, despite the inflammatory process, were able to prevent the osteonecrosis. In the 15-day euthanasia group, an increase in red blood cells and platelets was observed in the subgroup II. Hemoglobin and hematocrit decreased in subgroup IV compared to II. Hepatic transaminases and creatinine concentration increased significantly in subgroup II. Calcium concentration increased in subgroup IV compared to II. In the 30-day euthanasia group, no differences among the groups were observed for any parameter. Scaffolds proved to be efficient and safe to liver and kidney function. Some hematological parameters were altered by the scaffold, but returned to normal concentrations over time. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1799-1808, 2018.

Bacterial Nanocellulose Loaded with Bromelain: Assessment of Antimicrobial, Antioxidant and Physical-Chemical Properties.

Bacterial nanocellulose (BNC) has desirable properties for wound healing such as high purity, good shape retention, and high water binding capacity. Bromelain is a protease found in pineapple tissues and has been applied in several fields, it has anti-inflammatory and anticancer properties, promotes cell apoptosis, amongst others. In this work, a BNC based device for the controlled release of bromelain was developed. BNC were submersed in sterilized bromelain solution and incubated at 25 °C under 100 rpm for 24 h. Physical-chemical properties, protein concentration, antioxidant and antimicrobial activities were measured. Results demonstrate that BNC could improve bromelain antimicrobial activity 9 times. Those findings allow concluding that bromelain is a promising molecule to be incorporated into BNC's. The BNC's characteristics seem to represent a new promising delivery system of the loaded biomolecule, and protected from external actions.

Bromelain Loading and Release from a Hydrogel Formulated Using Alginate and Arabic Gum.

An ideal wound dressing ensures a moist environment around the wound area and absorbs exudates from the wound surface. Topical application of bromelain to incised wounds has been shown to reprogram the wound microenvironment to promote effective tissue repair. Combining the characteristics of hydrogels and bromelain is therefore of great interest. Herein, we describe the development of a hydrogel, formulated using alginate and Arabic gum, for bromelain loading and release. The hydrogel formulation was evaluated using response surface methodology, considering the pH value and the concentration of alginate and Arabic gum. Bromelain loading and release were evaluated based on passive diffusion. Differential scanning calorimetry and Fourier transform infrared spectroscopy were performed to confirm bromelain immobilization in the hydrogel. The final hydrogel formulation had a swelling ratio of 227 % and incorporated 19 % of bromelain from a bromelain solution. Bromelain immobilization in the hydrogel was the result of hydrogen bond formation and was optimal at 4 °C after 4 h of contact. This evidence suggests that bromelain entrapment into a hydrogel is a promising strategy for the development of wound dressings that support the debridement of burns and wounds.

A novel dosage form for buccal administration of bupropion

Bupropion is an antidepressant used in the treatment of smoking. The purpose of this study was to prepare controlled-release hydrogel films for buccal administration of bupropion and investigate its physicochemical and cytotoxic properties. The films were prepared from ultrapure sodium carboxymethylcellulose, hydroxypropylmethylcellulose K4M, and medium-viscosity chitosan. Evaluation of film physicochemical characteristics was based on scanning electron microscopy, bupropion content, mechanical strength (burst strength, relaxation, resilience, and traction), and cytotoxicity. Bupropion content in bilayer films was 121 mg per 9 cm2. The presence of bupropion modified film mechanical strength, but did not compromise the use of this pharmaceutical form. As shown by the cytotoxicity results, films containing bupropion did not cause cellular damage. Bupropion administration in the form of hydrogel films is a potentially useful alternative in the treatment of smoking.

A bupropiona é um antidepressivo utilizado no tratamento do tabagismo. O objetivo deste trabalho foi a preparação de filmes hidrogelatinosos de liberação controlada para administração bucal de bupropiona. Os filmes foram preparados utilizando carboximetilcelulose sódica ultrapurificada, hidroxipropilmetilcelulose K4M e quitosana de média viscosidade. As características físico-químicas dos filmes foram avaliadas por microscopia eletrônica de varredura, teor de bupropiona, resistência mecânica (perfuração, relaxação, resiliência e tração) e citotoxicidade. Os resultados mostraram que os filmes em bicamada apresentaram teor de bupropiona de 121 mg por 9 cm2 de filme e que a bupropiona modifica a resistência mecânica dos filmes, sem, no entanto, inviabilizar o uso desta forma farmacêutica. Os estudos de citotoxicidade mostraram que as formulações dos filmes contendo bupropiona não causam dano celular. Este estudo mostrou que a bupropiona veiculada na forma de filme hidrogelatinoso pode ser uma alternativa útil no tratamento do tabagismo.