Veterinary Research Forum

Abstract Bone tissue engineering offers a potential alternative to conventional grafting by combining biocompatible scaffolds with biological stimulants. Polycaprolactone (PCL) is a biodegradable polyester with good mechanical strength and biocompatibility. Hydroxyapatite (HA) is a calcium phosphate mineral that is a major component of bone and has excellent bioactivity and biocompatibility. This research investigated the histopathological effects of PCL-HA nanocomposite scaffolds along with their combination with platelet-rich fibrin (PRF), on the regeneration of bone in rabbit calvarial bone defects. Four circular full-thickness bone defects of 5.00 mm in diameter were created on the calvarial bone of 15 male New Zealand white rabbits. Three defects were filled with PRF, PCL-HA, and PCL-HA/PRF, and one defect was served as a control with no filler. Histopathological evaluations were conducted at 4-, 8-, and 12-weeks post-implantation. Data were evaluated using the Kruskal-Wallis and Mann-Whitney U tests. Significant differences were observed between the treatment and control groups regarding bone regeneration throughout all 12^th weeks studied. In the 4^th weeks, no significant differences in bone regeneration were noted among the treatment groups. In the 8^th weeks, most new bone formation was observed in the PCL-HA/PRF group. Both the PCL-HA and PCL-HA/PRF groups significantly improved bone regeneration compared to the control and PRF groups, with the PCL-HA/PRF group demonstrating the greatest bone formation, and vascularization and the lowest inflammation by the 12^th week. Thus, PCL-HA/PRF could be considered as a suitable alternative to bone grafts and could be increasingly utilized in orthopedic surgery and bone tissue engineering.

Abstract Spinal cord injury (SCI) presents challenging and unpredictable neurological recovery. During inflammatory conditions, the amount of serum albumin and nutrition consumption decreases. Currently, it is proposed to measure serum albumin and glucose content in human or animal subjects to predict the recovery rate and the efficiency of treatments following SCI. In this study, the effect of extra-cellular vesicles (EVs) from immortalized human adipose tissue-derived mesenchymal stem cells (hTERT-MSCs) equipped with the ectopic expression of the human indoleamine 2,3-dioxygenase-1 (IDO1) gene on serum albumin and glucose levels was investigated. After pre-clearing steps of 72-hr conditioned media, small EVs (sEVs) were isolated based on the ultra-filtration method. They were encapsulated with a chitosan-based hydrogel. Five experimental groups (female rats, N = 30, ~ 230 g) were considered, including SCI, sham, hydrogel, control green fluorescent protein (GFP)-EVs and IDO1-EVs. The 60.00 µL of hydrogel or hydrogels containing 100 µg sEVs from GFP or IDO1-EVs were locally injected immediately after SCI (laminectomy of the T10 vertebra and clip compression). After 8 weeks, non-fasting serum glucose and albumin levels were measured. The results indicated that the level of serum albumin in the animals received IDO1-EVs (3.52 ± 0.04) was increased in comparison with the SCI group (3.00 ± 0.94). Also, these animals indicated higher glucose levels in their serum (250.17 ± 69.61) in comparison with SCI ones (214 ± 45.34). Although these changes were not statistically significant, they could be considered as evidence for the beneficial effects of IDO1-EVs administration in the context of SCI to reduce hypoalbuminemia and improve energy consumption. More detailed experiments are required to confirm these results.

Abstract The development of tooth is a complex process wherein there is a series of interactions between the ectoderm and ectomesenchyme. Hyperdontia (also called supernumerary teeth) is a developmental abnormality being additional to the normal series of teeth with unknown etiology and is rare in ruminants. In this report, a rare case with two abnormal teeth outside the alveolar region, observed in a healthy 3-month-old female lamb was presented. The congenital defect consisted of the presence of 2 teeth positioned bilaterally in the caudal part of the mandible ramus and under the prominent pendulous skin; so, with retraction of prominent pendulous skin, these ectopic teeth were seen outside of the skin. The anomaly was found during a routine physical examination and no other congenital abnormalities were found in the lamb. The etiology of supernumerary teeth is not completely understood. This odontogenic abnormality appears to be an extraordinarily rare condition. Genetic, toxic, infectious or environmental factors related to congenital abnormalities affect the tooth growth. Depending on the supernumerary teeth position, surgery may be required.