Deni Noviana

In vitro and in vivo degradation evaluation of novel iron-bioceramic composites for bone implant applications.

Biodegradable metals such as magnesium, iron and their alloys have been known as potential materials for temporary medical implants. However, most of the studies on biodegradable metals have been focusing on optimizing their mechanical properties and degradation behavior with no emphasis on improving their bioactivity behavior. We therefore investigated the possibility of improving iron biodegradation rate and bioactivity by incorporating various bioactive bioceramics. The iron-based bioceramic (hydroxyapatite, tricalcium phosphate and biphasic calcium phosphate) composites were prepared by mechanical mixing and sintering process. Degradation studies indicated that the addition of bioceramics lowered the corrosion potential of the composites and slightly increased their corrosion rate compared to that of pure iron. In vitro cytotoxicity results showed an increase of cellular activity when rat smooth muscle cells interacted with the degrading composites compared to pure iron. X-ray radiogram analysis showed a consistent degradation progress with that found in vivo and positive tissue response up to 70 days implantation in sheep animal model. Therefore, the iron-based bioceramic composites have the potential to be used for biodegradable bone implant applications.

Evidences of in vivo bioactivity of Fe-bioceramic composites for temporary bone implants.

Iron-bioceramic composites have been developed as biodegradable implant materials with tailored degradation behavior and bioactive features. In the current work, in vivo bioactivity of the composites was comprehensively studied by using sheep animal model. Five groups of specimens (Fe-HA, Fe-TCP, Fe-BCP composites, and pure-Fe and SS316L as controls) were surgically implanted into medio proximal region of the radial bones. Real-time ultrasound analysis showed a decreased echo pattern at the peri-implant biodegradation site of the composites indicating minimal tissue response during the wound healing process. Peripheral whole blood biomarkers monitoring showed a normal dynamic change of blood cellular responses and no stress effect was observed. Meanwhile, the released Fe ion concentration was increasing along the implantation period. Histological analysis showed that the composites corresponded with a lower inflammatory giant cell count than that of SS316L. Analysis of the retrieved implants showed a thicker degradation layer on the composites compared with pure-Fe. It can be concluded that the iron-bioceramic composites are bioactive and induce a preferable wound healing process.

Distribution, Histochemical and Enzyme Histochemical Characterization of Mast Cells in Dogs

This study describes the distribution, proteoglycan properties and protease activity of mast cells from 15 different dog organs. In beagles and mixed breed dogs, staining with Alcian Blue–Safranin O revealed mast cells in all the organs examined. However, their numbers varied and they demonstrated unique localization patterns within some of these organs. Berberine sulphate fluorescence-positive mast cells were observed in the submucosa, muscularis and serosa of the intestines, as well as the tongue and liver (within the connective tissue). Mast cells within the intestinal mucosa were negative for, or demonstrated weak, berberine sulphate staining. Heterogeneity of mast cells in terms of the proteoglycans contained within their granules was further confirmed by determination of critical electrolyte concentrations (CECs). The CECs of mast cells within the connective tissue of several organs, including the intestines (submucosal and muscularis–serosal layers) were all greater than 1.0 M. The results from CEC experiments together with berberine staining indicate that heparin was contained within their granules. Relative to the CECs of mast cells in other organs, mast cells in the intestinal mucosa exhibited lower CECs, suggesting that the proteoglycans within their granules were of lower charge density and/or molecular weight. Although mast cells were classified into two groups by proteoglycans within the granules, enzyme histochemical analysis in beagles revealed three subtypes of mast cells: chymase (MCC), tryptase (MCT) and dual positive (MCTC) cells. There was no correlation between the proteoglycan content and enzyme properties of the mast cell granules.

Distribution and enzyme histochemical characterisation of mast cells in cats.

Mast cells from 15 different cat organs were examined in terms of distribution and protease activity. The number of mast cells in each site was found to vary when visualised by metachromatic staining using Alcian Blue. Enzyme histochemical analysis revealed the existence of two subtypes of mast cells. These were categorised based on protease content, i.e. whether the mast cells contained chymase or tryptase. Tryptase-positive mast cells were clearly identifiable in every organ examined, whereas chymase-containing mast cells were predominantly observed in the ear (skin), tongue, spleen, and submucosa of the stomach and rectum. The chymase-reactive cells were not detected in the heart, or in the muscularis or serosa of the duodenum, jejunum, ileum or rectum. In addition, we suggest the existence of another subtype of mast cell containing both chymase and tryptase and localised within the ear (skin), tongue, spleen and submucosa of the rectum.

Animal Study and Pre-clinical Trials of Biomaterials

An in vivo study is one of the most important steps in the process of translating biomaterials to clinical applications. It is mostly conducted to confirm in vitro results before going further to clinical trials. Appropriate use of animal models in the in vivo studies of biomaterials and medical devices is mandatory and should meet the approved regulations and ethics as defined by both local and international regulatory bodies. These studies involve the use of various approaches and protocols in order to know the body responses both local and systemic and to find out the short- and long-term responses of the body toward the implanted biomaterials or devices. This chapter describes complete procedures and practices of in vivo studies starting from selection of appropriate animal model, pre-implantation, surgical procedure and post-implantation, and monitoring of material-host responses. Some experiences of in vivo studies done by Indonesian researchers and the development of new implants are also presented.

The Evaluation of Hydroxyapatite (HA) Coated and Uncoated Porous Tantalum for Biomedical Material Applications

Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

Subjective and objective observation of skin graft recovery on Indonesian local cat with different periods of transplantation time

Aim: The success of a skin graft in a cat is highly dependent on the granulation formed by the base of recipient bed. Granulation by the base of recipient bed will form after several days after injury. This research aimed to observe subjective and objective profile of skin graft recovery on forelimb of cats with different periods of donor skin placement. Materials and Methods: Nine male Indonesian local cats aged 1-2 years old, weighing 3-4 kg were divided into three groups. The first surgery for creating defect wound of 2 cm×2 cm in size was performed in the whole group. The wound was left for several days with the respective interval for each group, respectively: Group I (for 2 days), Group II (for 4 days), and Group III (for 6 days). In the whole group, the second surgery was done by the harvesting skin of thoracic area which then applied on recipient bed of respective groups. Result: The donor skin on Group II was accepted faster compared to Group I and Group III. The donor skin did not show color differences compared to surrounding skin, painless, bright red in bleeding test had faster both hair growth and drug absorption. Test toward the size of donor skin and the effect of drugs did not show a significant difference between each group. Conclusion: The observe subjective and objective profile of skin graft recovery on forelimb of cats on Group II were accepted faster compared to Group I and III.

In vivo study of hydroxyapatite-chitosan and hydroxyapatite-tricalcium phosphate bone graft in sheep's bone as animal model

This study describes the in vivo evaluation study of bones implanted with graft of hydoxyapatite-chitosan (HA-C) and hydroxyapatite-tricalcium phosphate (HA-TCP) composite in sheeps bone as the animal model for human. This study was done in two parts, non-invasive clinical imaging study, i.e. brightness mode ultrasound (B-mode US) and conventional radiography (CR) technique, and morphological study of the bone healing process. Six sheep were used in this study and separated in two groups, three sheep for each group. The implantation surgery was done aseptically by creating a 4 mm diameter and 7 mm depth hole on each left and right hind limb of proximal medial tibial bone. First group implanted of HA-TCP at the left tibial and the second group by the HA-C composite. The right tibial of both groups served as control, which was drilled but not implanted. The CR and US were performed one day before and 7, 21, 30 days after implantation. Bones were harvested after 30, 60, and 90 days post-surgery and observed for morphological study. The B-mode US showed that inflammation and early bone remodeling occurred of both implants at subcutaneus area seven days after implantation and decreased 30 days after. Furthermore, the CR technique showed that both implant were still intact on site 90 days after, therefore, indicated minimal absorption or even not absorbed at all. The morphological evaluation showed that HA-TCP had been degradable 30 days after and continued, indicated signs for biocompatibility, biodegradability, bioresorbable, bioactivity and osteo conductivity properties. On the other hand, HA-C graft showed only biocompatibility characteristics 90 days after implantation. The result showed that the healing process of HA-TCP faster than HA-C but nevertheless, both composite still slower healing process than control bone.

Penanganan Obstruksi Duodenum pada Anjing: Laporan Kasus (Treatment of Duodenum Obstruction in Dogs: Case reports)

Veterinary Hospital of Education Faculty of Veterinary Medicine, Bogor Agricultural University, received a Golden Retriever with clinical symptoms of anorexia, abdominal pain, vomiting and constipation in April 2016. Blood profile examination showed leukocytosis, erythropenia and low hemoglobin level. Radiographic examination without contrast showed a foreign body which is characterized by a large mass radiopaque in intestinal area. Forty-five minutes after the administration of radiographic contrast, contrast material was still in gastrium and only reached partial intestinal. Endoscopy examination showed there was irritation symptoms of the esophagus to gastrium. Black colored liquid was seen while the endoscope inserted into the gastric. Enterotomy was carried out to remove foreign objects. The foreign body is consisted of bones fragments and the plastic that was eaten by the patient. One week after surgery, the animals showed clinical symptoms and had a good appetite. These case can be prevented by not giving foods that contain animal bones and keeping animals in a dirty environment.

Changes in histopathology and cytokeratin AE1/AE3 expression in skin graft with different time on Indonesian local cats

Aim: A good skin graft histopathology is followed by formation of hair follicle, sweat gland, sebaceous gland, blood vessel, lightly dense connective tissue, epidermis, and dermis layer. This research aimed to observe histopathology feature and cytokeratin AE1/AE3 expression on cat skin post skin grafting within a different period of time. Materials and Methods: Nine male Indonesian local cats aged 1-2 years old weighing 3-4 kg were separated into three groups. First surgery created defect wound of 2 cm × 2 cm in size to whole groups. The wounds were left alone for several days, differing in interval between each group, respectively: Group I (for 2 days), Group II (for 4 days), and Group III (for 6 days). The second surgery was done to each group which harvested skin of thoracic area and applied it on recipient wound bed. On day 24th post skin graft was an examination of histopathology and cytokeratin AE1/AE3 immunohistochemistry. Results: Group I donor skin’s epidermis layer had not formed completely whereas epidermis of donor skin of Groups II and III had completely formed. In all group hair follicle, sweat gland, sebaceous gland, and neovascularization were found. The density of connective tissue in Group I was very solid than other groups. Cytokeratin AE1/AE3 expression was found on donor skin’s epithelial cell in epidermis and dermis layer with very brown intensity for Group II, brown intensity for Group II, and lightly brown for Group I. Conclusion: Histopathological structure and cytokeratin AE1/AE3 expression post skin graft are better in Groups II and III compared to Group I.