Introduction: Whole body inverse kinetic models of humans are well developed. However, for animal models of human disease, the prevalent tools in human biomechanics do not exist. This work explores the development of whole body biomechanical models of quadrupeds, and presents preliminary results in the development of a whole body biomechanical model for sheep in OpenSIM, for use with motion capture data. We present statistical and machine learning models for predicting the hip joint centers from anatomical measurements and landmarks, as well as models for predicting the mass and inertial properties of sheep body segments.

Methods: CT scans from 16 sheep of varying ages, weight, sex, and phenotypes were acquired and the data used to calculate the known hip joint center by sphere fitting the femoral head. Anatomical measurements and additional subject information were used to create models to estimate the hip joint centers in absence of CT data. Then, the mass and moments of inertia for each body segment were estimated from the CT scans, and predictive models applied in the absence of CT scans.

Results: Hip joint centers were predicted with much greater accuracy than previous methods, with errors on the order of a few millimeters, depending on the animal. Mass and inertial properties were predicted with less accuracy, with errors typically within 10%, but in some cases exceeding 20%.

Conclusions: This work represents a significant new set of data for biomechanical models of sheep, being the first comprehensive study to include data from multiple animals. However, our data set is still limited, and would significantly benefit from a larger set of animals to be included. Additionally, sensitivity analysis on the models produced using this data will need to be performed to determine the extent to which errors in the various parameters affect final kinetic analyses.

Mouthwash, which commonly contains chemical antibacterial agents, is usually used to eliminate oral pathogens and maintain oral health. Herein, we aim to develop a chitosan (CS)-based drug-free mouthwash. CS is known to have great antibacterial activity in acidic conditions, but such acidity is not suitable for practical use, especially in the near-netrual oral environment. The antibacterial activity of CS in the near-neutral conditions is still unknown. In this work, we prepared a near-neutral CS solution-based mouthwash (pH ~6.0) and investigated its antioxidant and antibacterial activity. The CS mouthwash containing 200 μg/mL and 400 μg/mL CS showed a pH value of 6.03 and great antibacterial activity against both Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans (with a ~90% inhibition rate 3 h after incubation and an inhibition rate of almost 100% at 6 h). The antibacterial effects of CS mouthwash after 3 months show no significant differences compared to those 3 months ago, indicating the consistent and enduring antibacterial properties of CS mouthwash. The pH of the mouthwash also remained stable after 3 mouths. Damaged cell membranes and cell death were observed via SEM, which is considered to be the antibacterial mechanism. In addition, CS mouthwash caused no cytotoxicity to human oral keratinocytes and could protect human oral keratinocytes from damage under H2O2-induced oxidative stress. Also, CS mouthwash demonstrated the great capacity of intracellular ROS scavenging. This is the first report regarding the antibacterial and antioxidant activity of drug-free and near-neutral CS solution-based mouthwash. The oral-tolerated pH and the multiple functions of CS mouthwash give it great potential for clinical use. We will expand the study on the biofilms and compare the efficacy of CS with commercial products in the future.

Introduction

Collagen plays a crucial role in tissue engineering (TE) due to its fundamental properties and widespread presence in the extracellular matrix. In additional to providing structural support to tissues, collagen also contains cell adhesion domains promoting cell growth and differentiation, ideal for TE scaffolds. Fish skin collagen is gaining prominence as a sustainable biomaterial extracted from marine wastes and safe alternative to mammalian collagen due to minimal disease transmission risks, low religious constraints, biocompatibility. and easy biosorption in humans. This study exploits the potential of collagen from Skipjack Tuna fish as a bioactive material for skin TE.

Methods

The defatting and depigmentation of fish skin were performed in sodium hydroxide and butanol followed by acid soluble collagen extraction in acetic acid, and a precipitation method was conducted using sodium chloride. The sample was dialysed, lyophilised, and characterized. The collagen was further used an additive in hydrogel and electrospun scaffolds. Human dermal fibroblasts (HDFs) and mouse macrophages (RAW 264.7) were grown on the scaffolds with and without collagen and fixed for SEM imaging.

Results & Discussion

This extraction method yielded 10.02 ± 2.69 % of collagen from fish skin with a high hydroxyproline content of 14.42 ± 0.11 %. The FTIR spectrum showed the presence of amide bands A, B, I, II, and III, and SDS PAGE depicted the presence of α, β, and γ chains pertaining to collagen. SEM images showed the higher proliferation of HDFs on mats containing collagen compared to those without collagen. Collagen did not improve HDFs’ adhesion on hydrogels which proliferated as spheroids. Macrophages adopted an inactivated M0 morphology on collagenous hydrogels compared to an amoeboid shape with pronounced pseudopodia on non-collagenous hydrogels indicative of reduced inflammation in collagen’s presence.

Conclusion

Overall, while fish-derived collagen was found to improve cell proliferation on electrospun mats, it also reduced inflammatory response in hydrogel scaffolds.

Introduction: Metal–organic frameworks (MOFs) are highly porous networks composed of transition metal ions or clusters coordinated with organic ligands, offering versatile chemical functionalities. While recognized as effective antibacterial agents, their potential against severe pulmonary mycobacterial diseases remains underexplored. This study investigates Zn-MOF as an adjuvant for antimycobacterial drugs, demonstrating its significant efficacy against Mycobacterium smegmatis both alone and in combination with isoniazid and rifampicin.

Methods: Zn-MOF was synthesized via solvothermal reaction using Zinc nitrate hexahydrate (Zn²⁺ ion), 4,4'- bipyridyl (bridge), diphenyl phosphinic acid (organic linker), and dimethylformamide (solvent) at 85°C for 24 hours, yielding a white powder. Physical characterization involved FTIR, Raman, and XRD analyses. Antimycobacterial activity was assessed using a Colony-Forming Unit assay on M. smegmatis, a non-pathogenic model organism to study tuberculosis, evaluating Zn-MOF alone and in combination with isoniazid and rifampicin.

Results: FTIR, Raman Spectroscopy, and XRD confirmed the formation of Zn-MOF. The CFU assay demonstrated the superior antimycobacterial activity of Zn-MOF compared to standard drugs. Remarkably, synergistic effects were observed when combined with individual and dual therapies of rifampicin and isoniazid.

Conclusion: Zn-MOF shows promise as a novel adjuvant in tuberculosis treatment. Its efficacy against mycobacteria, especially in combination with first-line drugs, suggests its potential for developing innovative drug delivery systems. Understanding its mechanism could pave the way for enhanced therapeutic strategies against tuberculosis.

Introduction: Nitric oxide (NO) is known to alter coagulation by regulating platelet activity and plays a role in immunological response, infection prevention, and wound repair. Thus, NO-generating coatings have a high potential for wound healing applications. This study selected plasma polymerization to deposit a thin coating because of its high speed and low temperature, controlled film thickness, versatility on various surfaces, and environmental friendliness. Plasma modification offers the unique advantage of selectively enhancing surface properties without affecting the bulk attributes of the materials.

Methods: Plasma surface modification was carried out by using the high-frequency plasma system ZP-COVANCE-RFPE-3MP operating at 13.56 MHz at 15 W. Isopentyl nitrite (99.995%), C2H4 (99.95%), and Ar (99.998%) were used as precursors to deposit thin films on silicon wafers and polycaprolactone nanofibers at a pressure below 30 Pa. The obtained plasma-deposited polymer films were studied using SEM, EDX analysis, XPS, FTIR spectroscopy, and WCA. The kinetics of the release of NO were investigated by means of spectrophotometry. The adhesion and proliferation of human fibroblast cells on the surface of plasma-treated samples were studied. The samples were tested against different pathogens in terms of biofilm formation.

Results: Plasma deposition resulted in homogeneous and well-bonded layers. SEM micrographs showed no pinholes, cracks, or other damage in the deposited layers. According to FTIR and XPS, the obtained spectra indicated the presence of nitroxyl compounds on the surface of the samples. The difference in wettability of the samples was determined to be ≈90⁰. The deposited polymer coatings were shown to promote better proliferation of human fibroblast cells. The plasma-treated samples completely prevented biofilm formation.

Conclusions: An approach was developed for the deposition of nitroxyl-containing films from a mixture of isopentyl nitrite/C₂H₄ with improved proliferation of human cells and high antipathogenic activity.

The research was funded by the Russian Science Foundation (№24-79-10121).

The gold standard for chronic wound treatment involves the grafting of skin tissue, which is currently becoming replaced by cellular therapy. Studies indicate that cellular functions occur via paracrine signaling factors rather than direct interactions. This finding has initiated the exploration of secretome-based therapy. Platelets and MSCs are two critical cell types involved in wound healing. In the present study, we focused on analyzing the effect of the MSC secretome and platelet-induced MSC secretome on wound healing. Adipose tissue-derived MSCs (ADMSCs) and PRP were isolated from healthy rabbits (New Zealand White, 2 kg, 6 months) after obtaining Institutional Animal Ethics Committee clearance (SCT/IAEC-439/July/2022/113). In order to prepare PRP-induced ADMSC secretome, ADMSCs were seeded in a 75 Cm² culture flask at a density of 15000 cells/cm². At 70% confluency, the serum-containing culture medium was replaced with 450 µl PRP (350-400 x10³cells/µl)-containing media and cells were incubated for 48 hrs. Hyperglycemia was induced by growing fibroblasts in high-glucose (30mM) DMEM with 5% serum and antibiotics. The wound-healing efficiency of PRP-induced MSC secretome and uninduced MSC secretome was evaluated by means of on-cell proliferation, migration, collagen synthesis, ROS generation, actin cytoskeleton deposition, and gene expression analysis. All quantitative data were expressed as mean ± SD (n=3). Results were analyzed using one-way ANOVA/Student's t test and were considered significant when *p ≤ 0.05.

We observed that PRP-induced MSC secretome treatment significantly increased cell proliferation and migration, improved collagen synthesis, reduced ROS generation, and promoted actin deposition in hyperglycemic fibroblast cells compared to uninduced secretome treatment. In conclusion, these findings suggest that PRP-induced MSC-conditioned media may be developed as an off-the-shelf therapeutic aid. Further in vivo evaluation of PRP-induced MSC secretome needs to be performed in diabetic models, and the molecular pathways underlying its mechanism of action also need to be explored as future research perspectives.

Bioceramics are extensively used in bone tissue engineering, promoting tissue bonding, bone growth, and damage repair. Moreover, some bioceramics enhance the efficacy of skin healing by regulating the activity of various cell types (https://doi.org/10.1016/j.biomaterials.2022.121652). Given the absence of previous experimental studies, this work could contribute to the advancement of scientific knowledge in the area of ​​biomaterials. So, the objective of this study was to characterize and evaluate bioceramic powder samples with regard to their potential use in bone and skin regeneration. An optical microscopic analysis revealed that the morphology and size of the different bioceramic samples exhibited irregularities. The smallest particles were observed in the B2P, BG-2A, BG-2B, E1, F1, and G1 groups. The commercial 45S5 exhibited fine, pointed particles, whereas the B1P group had particles exceeding 100 μm in length. The E1 group exhibited the most negative zeta potential value, indicating that it was the most stable sample. In contrast, the B2P, BG-2A, BG-2B, F1, and G1 groups exhibited zeta potential values close to -25 mV, indicating that they exhibited moderate colloidal stability in suspension. Conversely, the B1P and 45S5 groups exhibited the least stable characteristics. An assessment of mitochondrial metabolism carried out on the MRC-5 fibroblast cell line exposed to the bioceramics using the MTT assay (n = 4 replicates/group) revealed that there was no significant impact on cell viability after 24 hours. These findings indicate that these new bioceramics possess favorable physicochemical properties and are not cytotoxic. The future prospects include the incorporation of bioceramics in bioinks for bone and skin regeneration.

Support: The Office of Naval Research Global (ONRG Award N62909-21-1-2026); National Institute of Science and Technology for Regenerative Medicine (INCT-Regenera); and Stem Cell Research Institute (IPCT).

Introduction: The use of animal models is widely spread in the scientific field, because the use of animals is essential for the transition from basic research to clinical research. Furthermore, there is no denying that the scientific advances achieved to date are related to the use of animal models. However, diminishing the usage of animals is desirable. One alternative to the use of animals are three-dimensional in vitro models that better mimic the tissue environment, allowing for more reliable results. The aim of this study was to produce and validate a 3D neuroinflammation model (3DNM) as an alternative for drug testing and alternative treatment approaches. Methods: The 3DNM was produced combining 5% alginate, 4% gelatin, 2x10⁵ PC12 cells, 4x10⁵ BV2 cells and 8x10⁵ C6 cells. Cell viability was evaluated with MTT assay. To test the anti-inflammatory potential of a bioink containing 1.5% decellularized spinal cord tissue, 3% gelatin, 4% sodium alginate and 7.5x10⁵ mesenchymal cells, the 3DNM was stressed with lipopolysaccharide (LPS) and treated with the bioink for three days. Reactive oxygen species (ROS) production and lipid peroxidation were measured. IL-6, IL-10 and IL-1B were quantified by ELISA. Non-enzymatic antioxidant defenses were evaluated by the quantification of Thiols. Results: MTT results demonstrated that the model was not cytotoxic to the cells because the viability increased when compared to the model stressed with the LPS. The bioink reduced the levels of ROS and pro-inflammatory cytokines on the 3DNM. TBARS assay showed that 3DNM lipid degradation was reduced when it was in contact with the bioink and was very close to that of the control. Thiols indicated that the bioink increased the non-enzymatic antioxidant defense in the 3DNM. Conclusion: The 3DNM showed promising results as an alternative model to study neural inflammation. This biomaterial may, therefore, be a solution for decreasing the laboratory use of animals.

Introduction: Hardystonite (HS, Ca₂ZnSi₂O₇) is a promising compound for bone tissue restoration due to its biocompatibility and good mechanical properties. However, it has too low a rate of dissolution in biological fluids, according to data in the literature. In this work, we propose a method of composite production based on Ca₂ZnSi₂O₇ and CaSiO₃ mixtures to increase the dissolution of HS materials.

Methods: Granules were synthesized by the emulsion method using mechanical mixtures of powdered β-wollastonite and ZnO (0, 0.5, 1.5, 2.5, 5, 10, 12.5, 15, 20, 25 wt.%), with gelatin as a binder. All syntheses were carried out in 10 parallels. Granules were heat-treated in air at 1250°C and analyzed using XRD, FTIR, TGA and SEM. Their fractional composition, true and average density, open porosity and solubility in Tris-HCl buffer were determined.

Results and Discussion: Spherical granules with a diameter of 0.1÷3 mm were synthesized. During heat treatment, the binder burns out (200÷500°C) and hardystonite is formed as a result of solid-state interaction between ZnO and CaSiO₃ (above 750°C). According to XRD and FTIR, variation in ZnO content in the initial powder leads to the formation of α-CaSiO₃ mixed with up to 96 wt.% Ca₂ZnSi₂O₇. The granules had a density >1 g/cm³ and open porosity of 60±5%. Materials can gradually dissolve in Tris-HCl buffer. Concentrations of ions in solutions decrease in the order Ca²⁺ > SiO₃^2– > Zn²⁺ at all time points. The less HS content in granules, the more Ca²⁺ and SiO₃^2– quantities and less Zn²⁺ in the surrounding media. Granules with 96 wt.% HS lost less than 0.5 wt.% in 6 months. A 2-fold decrease in HS content leads to a 25-fold increase in weight loss.

Conclusions: Composites with varying content of Ca₂ZnSi₂O₇ and CaSiO₃ were produced. Mixing with wollastonite allowed for a significant increase in the dissolution rate of HS-containing materials.

Surfactants comprise a wide range of chemical substances which continuously play important roles in human life due to their use as cleansing agents, among other applications. Their varied uses are due to their amphiphilic nature, which lowers the interfacial tension of two or more immiscible or insoluble substances through the supramolecular assembly complexation property, allowing for their utilization for cleansing purposes. Soaps/cleansers/detergents are commonly used consumer products and are an integral part of daily life. The soap market in India was estimated at USD 2.9 billion in FY2020 and is projected to grow to USD 4.4 billion by FY2026. The life cycle of toiletries has significant environmental impacts, so there is a necessity to use natural/biodegradable soap to minimize environmental harm. The intentional or unintentional release of chemical surfactants contaminates the environment. Using plant parts as soaps and detergents is an old practice in India and predates the discovery of chemical toiletries. Plants were used as substitutes of shampoo or conditioner. Using the rich heritage of traditional knowledge, these plants can be explored as bio-surfactants for the preparation of modern toiletry formulations, which can be used as alternative approach to toiletries to overcome the harmful effects of chemicals and protect the environment. The use of natural products in the formulation and development of toiletries will definitely help society in terms of the economy, healthcare, environmental protection, etc. Despite the traditional and ethno-botanical literature, there is limited scientific information available regarding pure herbal soaps. For this reason, the current work focuses on the future of plant-based bio-surfactants and aims at improving production efficiency, cost-effectiveness, biodegradability, and low toxicity, coupled with their mildness and compatibility with natural ingredients and environment-friendly formulations. These plant-based bio-surfactants constitute a promising and sustainable alternative approach to conventional synthetic surfactants in the toiletry industry.