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This study evaluated the biocompatibility of dense and porous forms of Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), Poly(ε-caprolactone) (PCL), and their 75/25 blend for bone tissue engineering applications. The biomaterials were characterized morphologically using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and the thickness and porosity of the scaffolds were determined. Functional assessments of mesenchymal stem cells (MSCs) included the MTT assay, alkaline phosphatase (ALP) production, and morphological and cytochemical analyses. Moreover, these polymers were implanted into rats to evaluate their in vivo performance. The morphology and FTIR spectra of the scaffolds were consistent with the expected results. Porous polymers were thicker than dense polymers, and porosity was higher than 92% in all samples. The cells exhibited good viability, activity, and growth on the scaffolds. A higher number of cells was observed on dense polymers, likely due to their smaller surface area. ALP production occurred in all samples, but enzyme activity was more intense in PCL samples. The scaffolds did not interfere with the osteogenic capacity of MSCs, and mineralized nodules were present in all samples. Histological analysis revealed new bone formation in all samples, although pure PHBV exhibited lower results compared to the other blends. In vivo results indicated that dense PCL and the dense 75/25 blend were the best materials tested, with PCL tending to improve the performance of PHBV in vivo. [ABSTRACT FROM AUTHOR]

Extrinsic thoracic limb muscles are a muscular group that supports the thoracic limb in mammals without the clavicle and serve to move the scapula and shoulder joint. However, there are few evolutionary studies of these muscles in Felis catus, which should take into account the topology and innervation of the muscles to hypothesize the muscle derivation from a common ancestor. The main objective of this study was to check the extrinsic thoracic limb muscles in ten cadavers. Intra‐ and interspecific anatomical variants were found with that formerly described and other felids. Based on the topology and innervation found in this study, the evolutionary derivation was hypothesized. Therefore, the omotransversarius and rhomboideus muscles are derived from the serratus ventralis cervicis muscle. The cleidobrachialis muscle is derived mainly from the m. deltoideus and accessorily from the supracoracoid muscular group. The pectoantebrachialis and pectoralis abdominalis muscles are derived from the pectoralis descendens and cutaneus trunci muscles, respectively. In conclusion, most extrinsic thoracic limb muscles of F. catus may have evolutionary derivations from the last common ancestor of mammals, while some of them are from the last common ancestor of carnivorans or within the family Felidae. [ABSTRACT FROM AUTHOR]

Type 1 diabetes mellitus (T1DM) is a chronic condition primarily managed with insulin replacement, leading to significant treatment costs. Complications include vasculopathy, cardiovascular diseases, nephropathy, neuropathy, and reticulopathy. Pancreatic islet transplantation is an option but its success does not depend solely on adequate vascularization. The main limitations to clinical islet transplantation are the scarcity of human pancreas, the need for immunosuppression, and the inadequacy of the islet isolation process. Despite extensive research, T1DM remains a major global health issue. In 2015, diabetes affected approximately 415 million people, with projected expenditures of USD 1.7 trillion by 2030. Pancreas transplantation faces challenges due to limited organ availability and complex vascularization. T1DM is caused by the autoimmune destruction of insulin-producing pancreatic cells. Advances in biomaterials, particularly the extracellular matrix (ECM), show promise in tissue reconstruction and transplantation, offering structural and regulatory functions critical for cell migration, differentiation, and adhesion. Tissue engineering aims to create bioartificial pancreases integrating insulin-producing cells and suitable frameworks. This involves decellularization and recellularization techniques to develop biological scaffolds. The challenges include replicating the pancreas's intricate architecture and maintaining cell viability and functionality. Emerging technologies, such as 3D printing and advanced biomaterials, have shown potential in constructing bioartificial organs. ECM components, including collagens and glycoproteins, play essential roles in cell adhesion, migration, and differentiation. Clinical applications focus on developing functional scaffolds for transplantation, with ongoing research addressing immunological responses and long-term efficacy. Pancreatic bioengineering represents a promising avenue for T1DM treatment, requiring further research to ensure successful implementation. [ABSTRACT FROM AUTHOR]

Bone defects in animals can arise from various causes, including diseases, neoplasms, and most commonly, trauma. Comminuted fractures that exceed the critical size may heal poorly due to deficient or interrupted vascularization, resulting in an insufficient number of progenitor cells necessary for bone regeneration. In this context, 3D printing techniques using poly-L-lactic acid/graphene oxide (PLLA/GO) aim to address this issue by creating customized scaffolds combined with canine placenta hydrogel and mesenchymal stem cells for use in goat mandibles, compared to a control group using titanium plate fixation. Ten canine placentas were decellularized and characterized using histological techniques. A hydrogel derived from the canine placenta extracellular matrix (cpECM) was produced to improve cell attachment to the scaffolds. In vitro cytotoxicity and cell adhesion to the cpECM hydrogel were assessed by scanning electron microscopy (SEM). The resulting biomaterials, cpECM hydrogel and PLLA/GO scaffolds, maintained their functional structure and supported cell adhesion, maintenance, and proliferation in vitro. Thermography showed that PLLA/GO scaffolds with cpECM hydrogel performed effectively, similar to the control group. Computed tomography scans revealed bone calluses, suggesting an ongoing repair process. These findings demonstrate the innovative technological potential of these materials for use in surgical interventions. Future studies on PLLA/GO scaffolds will provide further insights into their effects on goat models. [ABSTRACT FROM AUTHOR]

The temporomandibular joint (TMJ) ligaments play crucial roles in its function or dysfunction. The objective of this study was to describe the macro and microscopic morphology of these ligaments in domestic pigs, aiming to: (1) expand knowledge about the species; (2) provide anatomical references for advancing veterinary therapy and utilizing pigs as animal models in craniofacial research. Heads of young Sus scrofa domesticus were dissected to identify TMJ ligaments. Fragments of these ligaments were collected and processed for subsequent histological analysis with Haematoxylin and eosin staining. The results were qualitatively described. Pigs exhibited a TMJ reinforced by three individualized capsular ligaments: a lateral ligament, attaching to the ventral margin of the zygomatic process of the temporal bone and the lateral margin of the mandibular neck; a caudomedial ligament, attaching to the retroarticular process of the squamous part of the temporal bone and the caudomedial margin of the mandibular neck and a caudolateral ligament, attaching to the ventral margin of the base of the zygomatic process of the temporal bone and the caudal margin of the mandibular neck. The lateral ligament exhibited a greater constitution of dense irregular connective tissue, while the caudomedial and caudolateral ligaments showed a greater constitution of dense regular connective tissue. It is concluded that the TMJ of pigs presents one more ligament than horses, cattle, dogs, cats and what has been described for pigs themselves. We believe these results may contribute to the improvement of veterinary clinical and surgical therapy overall, as well as provide essential morphological information for a better interpretation and application of interspecies results in craniofacial research using pigs as an experimental model, as in the case of humans. [ABSTRACT FROM AUTHOR]

Simple Summary: For a pregnancy to begin, the embryo must "communicate" its presence to the mother's body to prevent rejection. Also, the embryo must attach to the uterine lining (a process called implantation) to form the placenta, the organ that supports embryo growth. This review discusses how mammal embryos achieve these critical steps and how embryonic communication signals and implantation types have changed throughout mammalian history. Embryos release substances, such as proteins and hormones, to signal their presence to the mother's body. These signals are species-specific, indicating that mammals have developed diverse mechanisms for pregnancy recognition. Implantation varies across mammal species. In most mammals, embryos attach to the surface of the uterine lining. This type of implantation has existed since the first mammals appeared on Earth and is widespread today, occurring in elephants, squirrels, horses, cows, whales, and many others. In some species, embryos partially or fully embed within the uterine wall. These implantation types have arisen many times in distantly related mammals, such as bats, rats, and great apes, including humans. Despite recent advancements, there is still much to discover. Future research should prioritize certain rodent and bat species to better understand how pregnancy recognition and implantation have evolved over time. The implantation of the embryo into the maternal endometrium is a complex process associated with the evolution of viviparity and placentation in mammals. In this review, we provide an overview of maternal recognition of pregnancy signals and implantation modes in eutherians, focusing on their diverse mechanisms and evolutionary patterns. Different pregnancy recognition signals and implantation modes have evolved in eutherian mammals, reflecting the remarkable diversity of specializations in mammals following the evolution of viviparity. Superficial implantation is the ancestral implantation mode in Eutheria and its major clades. The other modes, secondary, partially, and primary interstitial implantation have each independently evolved multiple times in the evolutionary history of eutherians. Although significant progress has been made in understanding pregnancy recognition signals and implantation modes, there is still much to uncover. Rodents and chiropterans (especially Phyllostomidae) offer valuable opportunities for studying the transitions among implantation modes, but data is still scarce for these diverse orders. Further research should focus on unstudied taxa so we can establish robust patterns of evolutionary changes in pregnancy recognition signaling and implantation modes. [ABSTRACT FROM AUTHOR]