The Development and Characterisation of A Porcine Large Intestinal Biological Scaffold by Perfusion Decellularisation

The rising incidence of colorectal cancer and ulcerative colitis underscores an urgent need for regenerative solutions to address functional deficits after colectomy. However, the creation of clinically applicable large intestine scaffolds remains underdeveloped. Here, we report the successful generation and thorough characterisation of transplantable-sized porcine large intestinal scaffolds via perfusion decellularisation. This method effectively preserved extracellular matrix (ECM) structural and biochemical integrity while minimising immunogenicity through cellular component removal. Crucially, native vasculature remained intact, confirmed by histology, DNA quantification, and high-resolution CT angiography. Despite efficient decellularisation, challenges including residual nucleic acids, ECM heterogeneity, and partial microvascular occlusion were noted, echoing ongoing limitations in engineered, perfusable, full-thickness scaffolds. In vivo implantation demonstrated favourable biocompatibility and host integration; however, thrombosis occurred due to the lack of pre-seeded cells, emphasising the necessity of recellularisation for functional perfusion prior to implantation. This study addresses significant field limitations, presenting the first reproducible approach for structurally intact, perfusable, full-thickness large intestinal scaffolds of transplantable dimensions. Our innovations offer a strong foundation for future integration of patient-derived cells, stem cells, and organoids, progressing toward clinically viable, scalable, tissue-engineered large intestine constructs, from xenogeneic sources, relevant for regenerative medicine, disease modelling, and pharmacological screening

Mechanisms underlying heterologous skin scaffold-mediated tissue remodeling

Biocompatibility of two newly developed porcine skin scaffolds was assessed after 3, 14, 21 and 90 days of implantation in rats. Both scaffolds showed absence of cells, preservation of ECM and mechanical properties comparable to non-decellularised skin before implantation. Host cell infiltration was much prominent on both scaffolds when compared to Permacol (surgical control). At day 3, the grafts were surrounded by polymorphonuclear cells, which were replaced by a notable number of IL-6-positive cells at day 14. Simultaneously, the number of pro-inflammatory M1-macrophage was enhanced. Interestingly, a predominant pro-remodeling M2 response, with newly formed vessels, myofibroblasts activation and a shift on the type of collagen expression was sequentially delayed (around 21 days). The gene expression of some trophic factors involved in tissue remodeling was congruent with the cellular events. Our findings suggested that the responsiveness of macrophages after non-crosslinked skin scaffolds implantation seemed to intimately affect various cell responses and molecular eventsand this range of mutually reinforcing actions was predictive of a positive tissue remodeling that was essential for the long-standing success of the implants. Furthermore, our study indicates that non-crosslinked biologic scaffold implantation is biocompatible to the host tissue and somehow underlying molecular events involved in tissue repair.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fed Univ Sao Paulo UNIFESP, Postgrad Struct & Funct Biol, BR-04023900 Sao Paulo, SP, BrazilSao Paulo State Univ UNESP, Dept Biol, BR-15054000 Sao Jose Do Rio Preto, SP, BrazilSao Paulo State Univ UNESP, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, BrazilUCL, Northwick Pk Inst Med Res, Dept Surg Res, London HA1 3UJ, Middx, EnglandPost-Graduation in Structural and Functional Biology, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, 04023-900, BrazilFAPESP: 2012/21603-2FAPESP: 2012/13041-4FAPESP: 2014/18557-4CNPq: 308144/2014-7CNPq: 245859/2012-8Web of Scienc

Antibacterial, Remineralising and Matrix Metalloproteinase Inhibiting Scandium-doped Phosphate Glasses for Treatment of Dental Caries

Objectives: Antibiotic resistance is increasingly a growing global threat. This study aimed to investigate the potential use of newly developed scandium-doped phosphate-based glasses (Sc-PBGs) as an antibacterial and anticariogenic agent through controlled release of Sc3+ ions. Methods: Sc-PBGs with various calcium and sodium oxide contents were produced and characterised using thermal and spectroscopic analysis. Degradation behaviour, ion release, antibacterial action against Streptococcus mutans, anti-matrix metalloproteinase-2 (MMP-2) activity, remineralisation potential and in vivo biocompatibility were also investigated. Results: The developed glass system showed linear Sc3+ ions release over time. The released Sc3+ shows statistically significant inhibition of S. mutans biofilm (1.2 log10 CFU reduction at 6 h) and matrix metalloproteinase-2 (MMP-2) activity, compared with Sc-free glass and positive control. When Sc-PBGs were mounted alongside enamel sections, subjected to acidic challenges, alternating hyper- and hypomineralisation layers consistent with periods of re- and demineralisation were observed demonstrating their potential remineralising action. Furthermore, Sc-PBGs produced a non-toxic response when implanted subcutaneously for 2 weeks in Sprague Dawley rats. Significance: Since Sc3+ ions might act on various enzymes essential to the biological mechanisms underlying caries, Sc-PBGs could be a promising therapeutic agent against cariogenic bacteria

Development of a novel hybrid bioactive hydrogel for future clinical applications

Three-dimensional hydrogels are ideal for tissue engineering applications due to their structural integrity and similarity to native soft tissues; however, they can lack mechanical stability. Our objective was to develop a bioactive and mechanically stable hydrogel for clinical application. Auricular cartilage was decellularised using a combination of hypertonic and hypotonic solutions with and without enzymes to produce acellular tissue. Methacryloyl groups were crosslinked with alginate and PVA main chains via 2-aminoethylmathacrylate and the entire macromonomer further crosslinked with the acellular tissue. The resultant hydrogels were characterised for its physicochemical properties (using NMR), in vitro degradation (via GPC analysis), mechanical stability (compression tests) and in vitro biocompatibility (co-culture with bone marrow-derived mesenchymal stem cells). Following decellularisation, the cartilage tissue showed to be acellular at a significant level (DNA content 25.33 ng/mg vs. 351.46 ng/mg control tissue), with good structural and molecular integrity of the retained extra cellular matrix (s-GAG= 0.19 μg/mg vs. 0.65 μg/mg ±0.001 control tissue). Proteomic analysis showed that collagen subtypes and proteoglycans were retained, and SEM and TEM showed preserved matrix ultra-structure. The hybrid hydrogel was successfully cross-linked with biological and polymer components, and it was stable for 30 days in simulated body fluid (poly dispersal index for alginate with tissue was stable at 1.08 and for PVA with tissue was stable at 1.16). It was also mechanically stable (Young’s modulus of 0.46 ± 0.31 KPa) and biocompatible, as it was able to support the development of a multi-cellular feature with active cellular proliferation in vitro. We have shown that it is possible to successfully combine biological tissue with both a synthetic and natural polymer and create a hybrid bioactive hydrogel for clinical application

Innovative organotypic in vitro models for safety assessment: aligning with regulatory requirements and understanding models of the heart, skin, and liver as paradigms

The development of improved, innovative models for the detection of toxicity of drugs, chemicals, or chemicals in cosmetics is crucial to efficiently bring new products safely to market in a cost-effective and timely manner. In addition, improvement in models to detect toxicity may reduce the incidence of unexpected post-marketing toxicity and reduce or eliminate the need for animal testing. The safety of novel products of the pharmaceutical, chemical, or cosmetics industry must be assured; therefore, toxicological properties need to be assessed. Accepted methods for gathering the information required by law for approval of substances are often animal methods. To reduce, refine, and replace animal testing, innovative organotypic in vitro models have emerged. Such models appear at different levels of complexity ranging from simpler, self-organized three-dimensional (3D) cell cultures up to more advanced scaffold-based co-cultures consisting of multiple cell types. This review provides an overview of recent developments in the field of toxicity testing with in vitro models for three major organ types: heart, skin, and liver. This review also examines regulatory aspects of such models in Europe and the UK, and summarizes best practices to facilitate the acceptance and appropriate use of advanced in vitro models

The distribution of small preantral follicles within the ovaries of prepubertal African elephants (Loxodonta africana)

BACKGROUND: Data on the distribution of primordial (single layer of squamous granulosa cells), early primary (some granulosa cells cuboidal) and primary (all granulosa cells cuboidal) follicles, grouped together as small follicles (SF) within the ovary of the elephant is lacking, yet such information is necessary to be able to estimate accurately the total numbers of small follicles in the ovaries of elephant throughout their lifespan. AIM: To determine if the density of SF differs between ovaries, between the surfaces of an ovary, or between the interpolar and intermarginal zones of an ovary. MATERIALS/METHODS: Stereological techniques were employed on 25 μm thick histological sections of the ovaries recovered from 12 prepubertal elephant calves aged 2 months to 4.5 years. Cell densities were calculated using the optical brick method and Cavalieri's principle for volume calculation. RESULTS: The density of SF (numbers of SF per unbiased counting frame [UCF]) did not differ between the left (1.11 ± 0.39 (mean ± sd)) and right (1.10 ± 0.39) ovaries (P = 0.82, n = 12), or between the lateral (median 1.24; interquartile range 0.85–1.39) and medial (1.03; 0.76–1.36) surfaces of the ovary (P = 0.22, n = 24) or among the 5 segments of the ovary between the two poles (P = 0.20, n = 24). The third of the cortex nearest to the mesovarial margin of the ovary had fewer small follicles per UCF (0.85; 0.51–1.28) than the middle third (1.01; 0.78–1.42; P = 0.034), and the third adjacent to the free margin (1.27; 0.79–1.51; P = 0.0024), n = 24 per group. CONCLUSION: Providing a random sample is taken from the full interpolar and intermarginal dimensions of ovary of a non-pregnant elephant, the density of small follicles throughout the cortex may be accurately measured using stereological techniques applied to one of its surfaces.http://www.elsevier.com/locate/anireprosciab201

Efficacy of a combination of Unani drugs in patients of Trichomonal vaginitis

727-730A controlled, randomized single blind clinical trial was conducted in women suffering from Trichomonal vaginitis. After confirming the clinical and microbiological diagnosis, the patients were divided into two groups. The patients in control group were administered Metronidazole in a dose of 200 mg three times a day, for seven days by oral route. While the patients in the test group were treated with a combination of Unani drugs, i.e. pills made of Afsanteen (Artemisia absinthium Linn.), Kabab Chini (Piper cubeba Linn.) and Bahroza (Pinus longifolia Roxb.) and capsule of Mazu (Gall of Quercus infectoria Oliv.), twice a day, for 10 days, by oral route. They were also treated with intravaginal tampon made of Barge Neem (Leaf of Azadirachta indica A. Juss.), Haldi (Rhizome of Curcuma longa Linn.) and Phitkiree (Alum), at bed time, for 10 days. The findings suggest that test drugs have been proved effective and safe in treatment of Trichomonal vaginitis

Self-Assembling Peptide Hydrogels - PeptiGels^® as a Platform for Hepatic Organoid Culture

AbstractA major challenge in advancing preclinical studies is the lack of robust in vitro culture systems that fully recapitulate the in vivo scenario together with limited clinical translational to humans. Organoids, as 3-dimensional (3D) self-replicating structures are increasingly being shown as powerful models for ex vivo experimentation in the field of regenerative medicine and drug discovery. Organoid formation requires the use of extracellular matrix (ECM) components to provide a 3D platform. However, the most commonly used ECM, essential for maintaining organoid growth is Matrigel and is derived from a tumorigenic source which limits its translational ability. PeptiGels® which are self-assembling peptide hydrogels present as alternatives to traditional ECM for use in 3D culture systems. Synthetic PeptiGels® are non-toxic, biocompatible, biodegradable and can be tuneable to simulate different tissue microenvironments. In this study, we validated the use of different types of PeptiGels® for porcine hepatic organoid growth. Hepatic organoids were assessed morphologically and using molecular techniques to determine the optimum PeptiGel® formulation. The outcome clearly demonstrated the ability of PeptiGel® to support organoid growth and offer themselves as a technological platform for 3D cultured physiologically and clinically relevant data.</jats:p