Tissue Integrity Research Articles

Exploring the frontier of Polylactic Acid/Hydroxyapatite composites in bone regeneration and their revolutionary biomedical applications – A review

This review research investigates the potential of Polylactic Acid (PLA)/Hydroxyapatite (HA) composites in bone regeneration, focusing on the composites’ synthesis methods, mechanical properties, and biocompatibility. Through an extensive examination of various preparation techniques, such as solvent evaporation, phase separation, electrospinning, and lyophilisation, the study assesses how these methods influence the physical and biological properties of PLA/HA composites. Significant findings from the review highlight that PLA/HA composites enhance osteoblast activity and proliferation, demonstrating an increase in cell adhesion by up to 25% compared to PLA alone. These composites substantially improve mechanical properties, increasing compressive strength and fracture toughness by approximately 30% and 50%, respectively. These enhancements are pivotal for applications requiring robust, load-bearing materials supporting bone tissue integration and regeneration. In conclusion, due to their optimised mechanical strength, biodegradability, and bioactivity, PLA/HA composites are promising biomaterials for orthopaedic and dental applications. The review suggests future research directions focused on long-term clinical outcomes and further material refinement to maximise clinical efficacy and patient compatibility.

Anti-Müllerian hormone in feline cryptorchidism: Serum levels, tissue expression, and implications for testicular health

Anti-Müllerian hormone (AMH) has become a pivotal subject in the study of testicular descent, maturation, integrity, and male fertility. Recent studies explored its roles and implications across various domestic species. A prominent approach involved the understanding of the modulation of AMH in reproductive disorders, including cryptorchidism. While substantial findings have been reported in dogs, ruminants, swine, and horses, data on AMH in feline cryptorchidism remains limited. Here, we aimed to bridge this gap by comparing AMH serum levels among cryptorchid, healthy intact, and castrated tomcats, employing an enzyme-linked immunosorbent assay (ELISA) kit for quantification. In addition, AMH expression in retained and descended testes was evaluated through immunohistochemistry, with positive staining quantified via pixel analysis in two distinct regions of interest: the seminiferous tubule and the interstitial space. Furthermore, tissue samples were subjected to histological evaluation and morphometric analysis, which included the calculation of seminiferous tubule areas (STA) and assessment of Johnsen scores. Thus, the relationship between AMH expression, altered testicular histology, and impaired spermatogenesis could be examined. The expression of AMH in retained and descended testes, was investigated, and the relationship between AMH expression, altered testicular histology, and impaired spermatogenesis was examined. Mean serum AMH levels differed significantly (P < 0.001) across the different groups being 15.35 ± 4.66 ng/mL (mean ± SD) in healthy intact tomcats (n = 15), 25.55 ± 2.86 ng/mL (mean ± SD) in cryptorchids (n = 10) and below 0.015 ng/mL in castrated cats (n = 10). STAs and Johnsen scores were significantly reduced in retained testes when compared to descended gonads (P < 0.01). Furthermore, serum AMH was negatively correlated with both the STA (ρ = −0.725, P < 0.001) and the Johnsen scores (ρ = −0.699, P < 0.001), suggesting its potential value for tissue integrity and spermatogenesis evaluation. In addition, positive immunostaining was significantly higher in retained testes (P < 0.05), especially in the interstitial space (P < 0.01), suggesting an involvement of the Leydig cells. Additionally, the increased interstitial expression was linked to the degree of tissue degeneration and the impaired spermatogenesis being negatively corelated with both Johnsen scores (ρ = −0.309, P < 0.01) and STA (ρ = −0.208, P < 0.05). Our findings underscore the potential of AMH in assessing testicular health and reveal possible interspecific differences, stressing the need for further investigation in cats.

Supplementation with Fish Oil and Selenium Protects Lipolytic and Thermogenic Depletion of Adipose in Cachectic Mice Treated with an EGFR Inhibitor.

Lung cancer and cachexia are the leading causes of cancer-related deaths worldwide. Cachexia is manifested by weight loss and white adipose tissue (WAT) atrophy. Limited nutritional supplements are conducive to lung cancer patients, whereas the underlying mechanisms are poorly understood. In this study, we used a murine cancer cachexia model to investigate the effects of a nutritional formula (NuF) rich in fish oil and selenium yeast as an adjuvant to enhance the drug efficacy of an EGFR inhibitor (Tarceva). In contrast to the healthy control, tumor-bearing mice exhibited severe cachexia symptoms, including tissue wasting, hypoalbuminemia, and a lower food efficiency ratio. Experimentally, Tarceva reduced pEGFR and HIF-1α expression. NuF decreased the expression of pEGFR and HIF-2α, suggesting that Tarceva and NuF act differently in prohibiting tumor growth and subsequent metastasis. NuF blocked LLC tumor-induced PTHrP and expression of thermogenic factor UCP1 and lipolytic enzymes (ATGL and HSL) in WAT. NuF attenuated tumor progression, inhibited PTHrP-induced adipose tissue browning, and maintained adipose tissue integrity by modulating heat shock protein (HSP) 72. Added together, Tarceva in synergy with NuF favorably improves cancer cachexia as well as drug efficacy.

Regulation of Osteogenic and Angiogenic Markers in Alkali Treated Titanium for Hard Tissue Engineering Applications.

Titanium (Ti) and Ti alloys are of great interest in bone and dental tissue engineering applications due to their biocompatibility, corrosion resistance, and close mechanical properties to natural bone. However, the formation of fibrous tissue prevents osteointegration and results in implant loosening. Thus, physical and chemical methods are used to improve the surface properties of Ti. This study aimed to understand the role of alkali treatment conditions, including alkali medium concentration, temperature, rotation speed, and post-heat treatment. Our results showed that alkali treatment using 5 and 10 molar sodium hydroxide solution allows the formation of web-like microstructure. However, a higher concentration of 15 molar resulted in cracks along the surface. Interaction between the human fetal osteoblast cells (hfOBs) and Ti samples showed that heat treatment is necessary for increased cellular proliferation, which was not significantly different at later time points compared to the polished Ti. Alkali heat treatment did not induce inflammatory reactions at later time points. It showed an increase in vascular endothelial growth factor, osteoprotegerin/nuclear factor kappa-В ligand ratio, and osteocalcin expression, which is evidence for accelerated osteoblast cell maturation and bone remodeling in surface-modified samples. Together, these data show that alkali treatment using 5 or 10 molar of NaOH followed by heat treatment may have therapeutic effect and assist with bone tissue integration with Ti implant.

Intelligent ultrasonic aspirator: Advancing tissue differentiation through hierarchical classification during hand-held resection

Modern neurosurgery strives to maximize tumor removal while preserving healthy tissue integrity. Accurate intraoperative differentiation between tumor and healthy tissue is crucial yet challenging. Often neurosurgeons rely on their experience and haptic feedback during palpation to distinguish between tumor and healthy tissue. A commonly used hand-held tool for tissue removal during neurosurgery is the ultrasonic aspirator, which changes its electrical properties as it interacts with tissue. The goal is to equip the ultrasonic aspirator with the ability to differentiate between different types of tissue while at the same time not interfering with the surgical workflow and providing comprehensible outcomes. To this end, a hierarchical classification approach is employed as a proof of concept, enabling precise identification of tissue stiffness during resection.The hierarchical approach is compared with the standard flat classification, commonly used in machine learning. Within the hierarchical approach, two strategies are employed: mandatory leaf-node predictions (MLNP) and non-mandatory leaf-node predictions (NMLNP). The NMLNP allows prediction to revert to a parent node when certainty is low. Data are acquired on three artificial tissue models – differing in stiffness – with an ultrasonic aspirator in a hand-held manner. The dataset comprises 1,821 data points for training and 186 for testing after balancing.The results indicate a slight performance advantage for the hierarchical classification MLNP approach over the flat classification approach in the absence of confidence thresholds, with weighted F2-scores of 0.781 and 0.762, respectively. However, the application of confidence thresholds results in both approaches exhibiting comparable performance, with the hierarchical NMLNP approach achieving a weighted F1-score of 0.920, thereby demonstrating superior overall performance. The effects of enforcing these thresholds and excluding data with low certainty are thoroughly investigated. This work emphasizes the feasibility of tissue differentiation using a hand-held ultrasound aspirator while resecting tissue. Moreover, it highlights the capability of hierarchical classification in advancing tissue differentiation accuracy during neurosurgical procedures, which could ultimately aid surgeons and enhance the safety of intraoperative workflows.

Innovations in Bioink Materials and 3D Bioprinting for Precision Tissue Engineering

The progress in bioink materials and 3D bioprinting techniques has created new opportunities in tissue engineering. The goal is to develop cellular implants that closely resemble native tissues in structure, function, and microenvironment, addressing challenges such as nutrient transport and mechanical support for tissue regeneration. This literature review evaluates current trends in bioink development and 3D bioprinting methodologies, assessing their effectiveness for enhancing tissue-engineered constructs for clinical applications. Recent studies were comprehensively analyzed, focusing on novel bioink formulations, optimization of 3D bioprinting processes, and evaluate on of printed constructs' mechanical and biological properties. Various fabrication techniques and their implications for tissue integration were examined. The review shows significant progress in bioink compositions that enhance cell viability and nutrient diffusion within printed scaffolds. Constructs demonstrated improved mechanical properties and biological functionality, enabling better integration with host tissues. In vivo studies highlighted the potential of these bioprinted tissues to support cellular activity and regeneration, signifying significant advancements in clinical viability. The findings emphasize the crucial role of bioink materials and bioprinting technology in advancing tissue engineering. Continual innovation in bioink formulation and printing techniques is essential to overcome current limitations and achieve widespread clinical application. Future research should focus on personalized bioink development and expanding the range of tissues that can be effectively engineered, ultimately improving patient outcomes in regenerative medicine.

Probing Nanotopography-Mediated Macrophage Polarization via Integrated Machine Learning and Combinatorial Biophysical Cue Mapping.

Inflammatory responses, leading to fibrosis and potential host rejection, significantly hinder the long-term success and widespread adoption of biomedical implants. The ability to control and investigated macrophage inflammatory responses at the implant-macrophage interface would be critical for reducing chronic inflammation and improving tissue integration. Nonetheless, the systematic investigation of how surface topography affects macrophage polarization is typically complicated by the restricted complexity of accessible nanostructures, difficulties in achieving exact control, and biased preselection of experimental parameters. In response to these problems, we developed a large-scale, high-content combinatorial biophysical cue (CBC) array for enabling high-throughput screening (HTS) of the effects of nanotopography on macrophage polarization and subsequent inflammatory processes. Our CBC array, created utilizing the dynamic laser interference lithography (DLIL) technology, contains over 1 million nanotopographies, ranging from nanolines and nanogrids to intricate hierarchical structures with dimensions ranging from 100 nm to several microns. Using machine learning (ML) based on the Gaussian process regression algorithm, we successfully identified certain topographical signals that either repress (pro-M2) or stimulate (pro-M1) macrophage polarization. The upscaling of these nanotopographies for further examination has shown mechanisms such as cytoskeletal remodeling and ROCK-dependent epigenetic activation to be critical to the mechanotransduction pathways regulating macrophage fate. Thus, we have also developed a platform combining advanced DLIL nanofabrication techniques, HTS, ML-driven prediction of nanobio interactions, and mechanotransduction pathway evaluation. In short, our developed platform technology not only improves our ability to investigate and understand nanotopography-regulated macrophage inflammatory responses but also holds great potential for guiding the design of nanostructured coatings for therapeutic biomaterials and biomedical implants.

Thiel cadaver eye as a training model for sub-Tenon’s blocks: a feasibility study

BackgroundRegional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon’s blocks by evaluating ocular tissues and measuring insertion forces.MethodsExperimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon’s blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye’s sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon’s blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig’s eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon’s blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon’s blocks and the emergence of a periocular “T-sign” ascertained and measured by ultrasound.ResultsFour of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon’s layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm–5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig’s eyes (3.6 N vs 2.0 N).ConclusionThese findings suggest that Thiel cadavers are a promising model for training in sub-Tenon’sblocks, despite the challenge of often desiccated and involuted eyes.

Effect of Chrysin and Chrysin Nanocrystals on Chlorpyrifos-Induced Dysfunction of the Hypothalamic-Pituitary-Testicular Axis in Rats.

The escalating global concerns regarding reproductive health underscore the urgency of investigating the impact of environmental pollutants on fertility. This study aims to focus on Chlorpyrifos (CPF), a widely-used organophosphate insecticide, and explores its adverse influence on the hypothalamic-pituitary-testicular axis in Wistar male rats. This study explores the potential protective effects of chrysin nanocrystal (CHN), a flavonoid with known antioxidant and anti-inflammatory properties, against CPF-induced impairments in male Wistar rats. Chrysin nanocrystals were prepared using a solvent precipitation method. Six sets of male Wistar rats were subjected to 30 days of treatment, comprising a control group, a group treated solely with CPF, groups treated with CHN at doses of 5 mg/kg and 10 mg/kg, and groups co-treated with CPF and CHN. Serum levels of reproductive hormones, enzyme biomarkers of testicular function, oxidative stress, and inflammatory biomarkers were assessed. Additionally, histological examinations were conducted on the hypothalamus, testes, and epididymis. CHN exhibited antioxidant and anti-inflammatory properties, effectively counteracting CPF-induced reductions in Luteinizing Hormone (LH), serum testosterone, Follicle-Stimulating Hormone (FSH), and testicular enzyme biomarkers. Moreover, CHN enhanced antioxidant defenses, as evidenced by decreased malondialdehyde (MDA) and increased glutathione (GSH) levels in the hypothalamus, and testes, epididymis. Inflammatory markers, including nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), were significantly reduced in CHN co-treated groups compared to the CPF-only group. Histopathological analyses confirmed the protective effects of CHN on tissue integrity. Chrysin nanocrystal demonstrated promising potential in mitigating CPF-induced reproductive deficits in male rats through its anti-inflammatory and antioxidant properties. This study provides valuable insights into therapeutic interventions against environmental toxin-induced reproductive toxicity, emphasizing the potential of chrysin nanocrystals as a protective agent in the context of CPF exposure.

Dynamic monitoring of a 3D-printed airway tissue model using an organic electrochemical transistor

Assessing the transepithelial resistance to ion flow in the presence of an electric field enables the evaluation of the integrity of the epithelial cell layer. In this study, we introduce an organic electrochemical transistor (OECT) interfaced with a 3D living tissue, designed to monitor the electrical resistance of cellular barriers in real-time. We have developed a non-invasive, tissue-sensing platform by integrating an inkjet-printed large-area OECT with a 3D-bioprinted multilayered airway tissue. This unique configuration enables the evaluation of epithelial barrier integrity through the dynamic response capabilities of the OECT. Our system effectively tracks the formation and integrity of 3D-printed airway tissues in both liquid-liquid and air-liquid interface culture environments. Furthermore, we successfully quantified the degradation of barrier function due to influenza A (H1N1) viral infection and the dose-dependent efficacy of oseltamivir (Tamiflu®) in mitigating this degradation. The tissue-electronic platform offers a non-invasive and label-free method for real-time monitoring of 3D artificial tissue barriers, without disturbing the cellular biology. It holds the potential for further applications in monitoring the structures and functions of 3D tissues and organs, significantly contributing to the advancement of personalized medicine.

Unraveling the molecular basis for effective regulation of integrin α5β1 for enhanced therapeutic interventions

Cell attachment to the extracellular matrix significantly impacts the integrity of tissues and human health. The integrin α5β1 is a heterodimer of α5 and β1 subunits and has been identified as a crucial modulator in several human carcinomas. Integrin α5β1 significantly regulates cell proliferation, angiogenesis, inflammation, tumor metastasis, and invasion. This regulatory role of integrin α5β1 in tumor metastasis makes it an appealing target for cancer therapy. The majority of the drugs targeting integrin α5β1 are limited only to clinical trials. In our study, we have performed 94287 compounds screening to determine potential drugs against α5β1 integrin. We have used ATN-161 as a reference and employed combined bioinformatic methodologies, including molecular modelling, virtual screening, MM-GBSA, cell-line cytotoxicity prediction, ADMET, Density Functional Theory (DFT), Non-covalent Interactions (NCI) and molecular simulation, to identify putative integrin α5β1 inhibitors. We found Taxifolin, PD133053, and Acebutolol that possess inhibitory activity against α5β1 integrin and could act as effective drug for the cancer treatment. Taxifolin, PD133053, and Acebutolol exhibited excellent binding to the druggable pocket of integrin α5β1, and also maintained a unique binding mechanism with extra hydrophobic contacts at molecular level. Overall, our study gives new pharmacological candidates that may act as a potential drug against integrin α5β1.

Biomimetic Surface Nanoengineering of Biodegradable Zn‐Based Orthopedic Implants for Enhanced Biocompatibility and Immunomodulation

AbstractZinc (Zn) is gaining increased recognition as a biodegradable metal in biomedical applications but clinical translation is limited due to its poor biocompatibility. This study addresses these issues through an innovative biomimetic strategy, introducing an efficient surface nanoengineering approach that creates nano‐geometric features and chemical compositions by modulating the exposure time to a biological medium – Dulbecco's Modified Eagle Medium(DMEM). These nanoengineered Zn implants exhibited tunable degradation rates. The nanostructures enhanced human osteoblast attachment, proliferation, and differentiation following direct contact, and improved macrophage function by promoting pseudopod formation and transitioning from a pro‐inflammatory M1 to a pro‐reparative M2 phenotype. In vivo studies show that the surface‐engineered implants effectively promoted tissue integration via M2 macrophage polarization, resulting in a favorable immunomodulatory environment, and increased collagen deposition. Proteomic analyses show that the tissues in the vicinity of the surface‐engineered Zn implants are enriched with proteins related to key wound healing biological mechanisms such as cell adhesion, cytoskeletal structural arrangement, and immune response. This study highlights the improved biocompatibility and anti‐inflammatory effects of surface‐engineered Zn, with important implications for the clinical translation of biodegradable Zn‐based orthopedic implants.

A cheminformatics and network pharmacology approach to elucidate the mechanism of action of Mycobacterium tuberculosis γ-carbonic anhydrase inhibitors.

Mycobacterium tuberculosis (Mtb) carbonic anhydrases (CAs) are critical enzymes that regulate pH by converting CO2 to HCO3 -, essential for Mtb's survival in acidic environments. Inhibiting γ-CAs presents a potential target for novel antituberculosis drugs with unique mechanisms of action. This study aimed to explore the biological connections underlying Mtb pathogenesis and investigate the mechanistic actions of antituberculosis compounds targeting the Cas9 protein. We employed homology modeling and virtual screening to identify compounds with high binding affinities for Cas9 protein. This study used the homology modeling approach employing high-quality AlphaFold DB models for γ-CA. Furthermore, the systems biology approach was used for analyzing the integrated modelling of compounds, integrating data on genes, pathways, phenotypes, and molecular descriptors. Single-cell RNA sequencing was also conducted to profile gene expression. Three compounds, F10921405, F08060425, and F14437079, potentially binding to Cas9 protein, have been identified. F10921405 and F08060425 showed significant overlap in their effects on pathways related to the immune response, while F14437079 displayed distinct mechanistic pathways. Expression profiling revealed high levels of genes such as PDE4D, ROCK2, ITK, MAPK10, and SYK in response to F1092-1405 and F0806-0425, and MMP2 and CALCRL in response to F1443-7079. These genes, which play a role in immune modulation and lung tissue integrity, are essential to fight against Mtb. The molecular relationship and pathways linked to the mentioned compounds give the study a holistic perspective of targeting Mtb, which is essential in designing specific therapeutic approaches. Subsequent research will involve experimental validation to demonstrate the efficacy of the promising candidates in Mtb infections.

Assessing the Viability of Polycaprolactone Mesh in Bilateral Orbital Floor Reconstruction: Insights From Le Fort II Fracture Cases.

This study aims to evaluate the effectiveness of pure polycaprolactone (PCL) mesh in reconstructing complex bilateral orbital floor fractures associated with Le Fort II fractures. PCL mesh is traditionally viewed as less suitable for severe fractures due to its perceived weakness. This study challenges that perception by demonstrating the utility of PCL mesh in high-severity cases. Two patients with Le Fort II fractures and bilateral orbital floor fractures underwent orbital reconstruction using a 3D-printed PCL mesh. The mesh was molded and inserted through subciliary or transconjunctival incisions. Orbital volumes were analyzed preoperatively and postoperatively using CT scans and a 3D Analysis program. Both cases demonstrated significant correction of orbital volume differences postoperatively, leading to improved symmetry and successful reconstruction. For case 1, the preoperative orbital volume difference of 3.2cc was reduced to 1.1cc postoperatively. For case 2, the preoperative orbital volume difference of 1.18cc was reduced to 0.4cc postoperatively. The PCL mesh provided adequate structural support and facilitated effective tissue integration. Despite the radiolucency of the PCL mesh on CT scans, volumetric analysis confirmed stable and balanced orbital volumes. Pure PCL mesh is a viable alternative for orbital floor reconstruction in severe craniofacial fractures, offering a balance of structural support and biocompatibility. To validate these findings, further research with larger samples and long-term follow-up is recommended.

Genetically Modified Porcine Kidneys Have Sufficient Tissue Integrity for Use in Pig-to-Human Xenotransplantation.

We sought to determine if genetically modified porcine kidneys used for xenotransplantation had sufficient tissue integrity to support long-term function in a human recipient. Kidney transplantation remains the best available treatment for patients with end-stage kidney disease. However, a shortage of available donor human kidneys prevents many patients from achieving the benefits of transplantation. Xenotransplantation is a potential solution to this shortage. Recent pre-clinical human studies have demonstrated kidneys from genetically modified pig donors can be transplanted without hyperacute rejection and are capable of providing creatinine and other solute clearance. It is unknown whether the porcine kidneys would tolerate the relatively higher resting blood pressure in an adult human recipient compared with the pig donor or non-human primate (NHP) recipients used in translational studies. Furthermore, previous experience in NHPs raised concerns about the tissue integrity of the porcine ureter and post-xenotransplant growth of the porcine kidney. Kidneys recovered from porcine donors with 10 gene edits were transplanted into decedent brain-dead recipients who were not eligible for organ donation. Decedents underwent bilateral native nephrectomy before transplant and were followed for 3 to 7 days. Standard induction and maintenance immunosuppression was used as previously reported. Vital signs, including blood pressure, were recorded frequently. Kidney xenografts were assessed daily, serially biopsied, and were measured at implantation and study completion. Three decedents underwent successful xenotransplantation. Subcapsular hematomas developed, requiring incision of the xenograft capsules to prevent Page kidney. Blood pressures were maintained in a physiologic range for adult humans (median arterial pressures (MAP) 108.5mmHg (Interquartile Range (IQR): 97-114mmHg), 74mmHg (IQR: 71-78mmHg), and 95mmHg (IQR: 88-99mmHg, respectively) and no bleeding complications or aneurysm formation was observed. Serial biopsies were taken from the xenografts without apparent loss of tissue integrity despite the lack of a capsule. Ureteroneocystotomies remained intact without evidence of urine leak. Xenograft growth was observed, but plateaued, in 1 decedent with increased volume of the left and right xenografts by 25% and 26%, respectively, and in the context of human growth hormone levels consistently less <0.1ng/ml and insulin-like growth factor 1 levels ranging from 34-50ng/ml. The findings of this study suggest kidneys from 10-gene edited porcine donors have sufficient tissue integrity to tolerate xenotransplantation into a living human recipient. There was no evidence of anastomotic complications, and the xenografts tolerated needle biopsy without issue. Xenograft growth occurred but plateaued by the study end; further observation and investigation will be required to confirm this finding and elucidate underlying mechanisms.

A Novel Hybrid Injectable for Soft-tissue Augmentation: Analysis of Data and Practical Experience

Background: HA/CaHa (HArmonyCa, Allergan Aesthetics, an AbbVie Company) is a hybrid injectable filler developed for aesthetic purposes that contains calcium hydroxyapatite microspheres suspended in a hyaluronic acid gel. This review describes preclinical and clinical data, recommendations for use based on the primary author’s clinical experience, and case studies that illustrate implementation of product use recommendations and patient outcomes. Methods: Preclinical data on the lift capacity and tissue integration of the HA/CaHa hybrid injectable and clinical data on its safety, efficacy, and real-world use were extracted from poster presentations, published literature, manufacturer instructions for use, and proprietary data files. Case studies were presented based on clinical experience. Results: The HA component of HA/CaHa provides an immediate and noticeable filling and lifting effect, whereas CaHa microspheres result in neocollagenesis. In preclinical studies, HA/CaHa demonstrated higher lift capacity (P &lt; 0.05) and faster tissue integration than a CaHa filler and led to collagen I gene and protein expression. Clinical studies showed clinical safety and effectiveness with high patient satisfaction. The most common adverse event was injection-site response. Clinician recommendations for achieving desired aesthetic results while minimizing or preventing adverse events are reviewed, including patient selection and assessment, treatment approaches based on face shape, injection technique, and postprocedure care. Conclusion: The novel hybrid injectable consisting of HA with incorporated CaHa microspheres in a single marketed product may help achieve aesthetic goals by immediately restoring volume and potentially improving skin architecture and soft-tissue quality over time.

Topography-guided Anatomical Reassembly for Distal Penile Hypospadias Without Chordee: A Comprehensive Illustration and Midterm Results of a Novel Approach

ObjectivesTo provide a comprehensive illustration of the newly introduced ‘topography-guided anatomical reassembly’ approach, which has shown promising early results, and to report the mid-term outcomes of an extended series. MethodsThis is a prospective cohort study of all patients presenting to the author’s facility with distal penile hypospadias without chordee between June 2018 and January 2023. Redo cases, circumcised cases, and cases with non-preservable plates are excluded. The procedure follows the most recently introduced principle of the topography-guided anatomical reassembly approach for distal penile hypospadias, that is, the exclusive zipping-up of the unfolded spongiosal plate. ResultsA subset of 97 boys met the enrolment criteria. The hypospadias meatus was coronal or sub-coronal in 35 boys, distal penile in 45 boys, and mid-penile in 17 boys. The mean age at the time of surgical correction was 8.11 months. The mean operative time was 66.7 min. After a mean follow-up of 27 months, five urethrocutaneous fistulae were reported: three glanular and two sub-coronal. Meatal disfigurement with downward stream deviation was reported in two more patients. Two more occurrences of meatal recession were identified, yet surgical correction was not necessary. The overall reoperation rate settled at 7%. ConclusionsThe proposed topography-guided anatomical reassembly technique for distal hypospadias is simple, effective, and highly feasible at mid-term follow-up of the given series. Maintaining the integrity of well-developed penile tissues eliminates the possibility of unforgivable tissue damage and avoids the need for challenging revision procedures.

Type III Collagen Regulates Matrix Architecture and Mechanosensing during Wound Healing

Post-natal cutaneous wound healing is characterized by development of collagen-rich scar lacking the architecture and functional integrity of unwounded tissue. Directing cell behaviors to efficiently heal wounds while minimizing scar formation remains a major wound management goal. Herein, we demonstrate type III collagen (Col3) as a critical regulator of re-epithelialization and scar formation during healing of Col3-enriched, regenerative (Acomys), scar-permissive (CD-1 Mus and wild-type Col3B6/B6 mice), and Col3-deficient, scar-promoting (Col3F/F, a murine conditional knockdown model) cutaneous wound models. We define a scar-permissive fibrillar collagen architecture signature characterized by elongated and anisotropically-aligned collagen fibers that is dose-dependently suppressed by Col3. Further, loss of Col3 alters how cells interpret their microenvironment - their mechanoperception - such that Col3-deficient cells display mechanically-active phenotypes in the absence of increased microenvironmental stiffness via upregulation and engagement of the profibrotic integrin α11. Further understanding Col3's role in regulating matrix architecture and mechanoresponses may inform clinical strategies that harness pro-regenerative mechanisms.

Benzo(a)pyrene exposure during pregnancy leads to germ cell apoptosis in male mice offspring via affecting histone modifications and oxidative stress levels

Infertility has gradually become a global health concern, and evidence suggests that exposure to environmental endocrine-disrupting chemicals (EDCs) represent one of the key causes of infertility. Benzo(a)pyrene (BaP) is a typical EDC that is widespread in the environment. Previous studies have detected BaP in human urine, semen, cervical mucus, oocytes and follicular fluid, resulting in reduced fertility and irreversible reproductive damage. However, the mechanisms underlying the effects of gestational BaP exposure on offspring fertility in male mice have not been fully explored. In this study, pregnant mice were administered BaP at doses of 0, 5, 10 and 20 mg/kg/day via gavage from Days 7.5 to 12.5 of gestation. The results revealed that BaP exposure during pregnancy disrupted the structural integrity of testicular tissue, causing a disorganized arrangement of spermatogenic cells, compromised sperm quality, elevated levels of histone modifications and increased apoptosis in the testicular tissue of F1 male mice. Furthermore, oxidative stress was also increased in the testicular tissue of F1 male mice. BaP activated the AhR/ERα signaling pathway, affected H3K4me3 expression and induced apoptosis in testicular tissue. AhR and Cyp1a1 were overexpressed, and the expression of key molecules in the antioxidant pathway, including Keap1 and Nrf2, was reduced. The combined effects of these molecules led to apoptosis in testicular tissues, damaging and compromising sperm quality. This impairment in testicular cells further contributed to compromised testicular tissues, ultimately impacting the reproductive health of F1 male mice.

Axolotl mandible regeneration occurs through mechanical gap closure and a shared regenerative program with the limb.

The mandible plays an essential part in human life and, thus, defects in this structure can dramatically impair the quality of life in patients. Axolotls, unlike humans, are capable of regenerating their lower jaws; however, the underlying mechanisms and their similarities to those in limb regeneration are unknown. In this work, we used morphological, histological and transcriptomic approaches to analyze the regeneration of lateral resection defects in the axolotl mandible. We found that this structure can regenerate all missing tissues in 90 days through gap minimization, blastema formation and, finally, tissue growth, differentiation and integration. Moreover, transcriptomic comparisons of regenerating mandibles and limbs showed that they share molecular phases of regeneration, that these similarities peak during blastema stages and that mandible regeneration occurs at a slower pace. Altogether, our study demonstrates the existence of a shared regenerative program used in two different regenerating body structures with different embryonic origins in the axolotl and contributes to our understanding of the minimum requirements for a successful regeneration in vertebrates, bringing us closer to understand similar lesions in human mandibles.