The exact causes of failure of anterior cruciate ligament (ACL) reconstruction are still unknown. A key to successful ACL reconstruction is the prevention of bone tunnel enlargement (BTE). In this study, a new strategy to improve the outcome of ACL reconstruction was analyzed using a bioresorbable polylactide (PLA) stent as a catalyst for the healing process. The study included 24 sheep with 12 months of age. The animals were randomized to the PLA group (n = 16) and control group (n = 8), subjected to the ACL reconstruction with and without the implantation of the PLA tube, respectively. The sheep were sacrificed 6 or 12 weeks post-procedure, and their knee joints were evaluated by X-ray microcomputed tomography with a 50 μm resolution. While the analysis of tibial and femoral tunnel diameters and volumes demonstrated the presence of BTE in both groups, the enlargement was less evident in the PLA group. Also, the microstructural parameters of the bone adjacent to the tunnels tended to be better in the PLA group. This suggested that the implantation of a bioresorbable PLA tube might facilitate osteointegration of the tendon graft after the ACL reconstruction. The beneficial effects of the stent were likely associated with osteogenic and osteoconductive properties of polylactide.

The aim of the work was to evaluate the in vivo biological behaviour of polymeric membrane materials for glaucoma implants. The base material was biostable synthetic terpolymer (PTFE–PVDF–PP) with proved biocompability (PN-EN ISO 10993). The samples manufactured in the form a membrane were subjected to chemical and physical treatment to create an open pore system within the polymer matrix. As a porogenic phase biodegradable natrium alginate in a fibrous form was employed. The non-perforating deep sclerectomy technique was performed in a rabbit model. The clinical observations were made after 14 and 30 days. During the study clinical symptoms of a moderate degree were observed, and histopathological changes were typical for foreign body implantation. At the end stage of the study no significant difference in histopathological assessment was found between control and experimental group. Similarities observed in both groups and relatively mild histopathological changes in the tissue surrounding the implant indicate that the observed symptoms come from a deep scleral trauma caused by surgery, and not by the presence of the implant itself.

The laparoscopic method of recovering oocytes in goats and sheep is one of the minimally invasive methods used in the biotechnology of animal reproduction. It allows for good quality oocytes that are suitable for in vitro maturation and fertilization to be recovered. The limitation of using the laparoscopic ovum pick-up (L-OPU) method in goat and sheep is its changing effectiveness and the lack of repeatability of results, as well as the varying effectiveness of different variants of the method. Therefore, it is necessary to develop effective non-invasive techniques allowing for multiple good quality oocyte recovery that would be suitable for in vitro maturation and fertilization. In this study, four different L-OPU variants were described in goats and sheep. Various techniques of recovering oocytes were discussed, including the techniques of conducting the operation, various tools for recovering oocytes, and different plans of hormonal stimulation. Recovery rates were 35% (Variant I), 57% (Variant II), 72% (Variant III), and 67% (Variant IV). After evaluation, 94% (both Variant I and II), 93% (Variant III), and 84% (Variant IV) of the oocytes were qualified for in vitro maturation. The results of the study show that the proposed technique of laparoscopic recovery of oocytes allows a sufficient number of ovarian cells suitable for in vitro culture to be obtained and as a consequence it makes them useful in in vitro maturation/in vitro fertilization (IVM/IVF) programs or cloning. The method allows for a fast and effective conduct of the operation in a living donor with minimal invasiveness while preserving the excellent condition of animals.

Osteoarthritis (OA) is a degenerative joint condition leading to disability. The lack of effective treatment for OA creates a need for the development of new therapeutic approaches that may rely on stem cells including mesenchymal stem/stromal cells (MSCs) and their derivatives such as extracellular vesicles (EVs). The objective of this study was to evaluate the impact of MSCs derived from adipose tissue (AT-MSCs) and umbilical cord (UC-MSCs) and their EVs on cartilage-bone injury in vivo, to identify the specimen with the highest regenerative potential for further clinical applications in patients with OA. Humanized pigs underwent cartilage-bone injuries followed by intraarticular administration of products containing AT-MSCs, UC-MSCs, AT-MSC-EVs or UC-MSC-EVs mixed with hyaluronic acid (HA) or HA alone (for comparison). After 6-m follow-up, almost-fully-healed cartilage-bone defects were observed in the AT-MSC- and UC-MSC-treated pigs, and the defects were filled primarily with hyaline cartilage. In AT-MSC-EV- and UC-MSC-EV-treated pigs, a partial cartilage-bone tissue repair was observed, and the defects were filled primarily with fibrocartilage. The control pigs demonstrated limited regeneration capacity. The microcomputed tomography parameters of the subchondral bone indicated the ongoing progression of OA in controls, whereas in the MSC- and MSC-EV-treated pigs, the parameters indicated the cessation of OA progression. Moreover, no serious side effects were observed after the administration of products containing MSCs or MSC-EVs. The results indicate the safety and regenerative activity of MSCs on injured tissues, which favors not only the healing and improvement of bone structure but also the formation of hyaline cartilage. Superior tissue repair was observed after the administration of products containing AT-MSCs. The treatment of OA with MSC-EVs needs further standardization. Graphical Abstract