ABSTRACT
Homeostatic programs balance immune protection and self-tolerance. Such mechanisms likely impact autoimmunity and tumor formation, respectively. How homeostasis is maintained and impacts tumor surveillance is unknown. Here, we find that different immune mononuclear phagocytes share a conserved steady-state program during differentiation and entry into healthy tissue. IFNγ is necessary and sufficient to induce this program, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify survival. Single-cell RNA sequencing (RNA-seq) reveals enrichment of homeostatic modules in monocytes and DCs from human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2) protein, a conserved program transcript, is expressed by mononuclear phagocytes infiltrating primary melanoma and is induced by IFNγ. SOCS2 limits adaptive anti-tumoral immunity and DC-based priming of T cells in vivo, indicating a critical regulatory role. These findings link immune homeostasis to key determinants of anti-tumoral immunity and escape, revealing co-opting of tissue-specific immune development in the tumor microenvironment.
Subject(s)
Interferon-gamma/immunology , Melanoma/immunology , Monocytes/immunology , Neoplasm Metastasis/pathology , Skin Neoplasms/immunology , Suppressor of Cytokine Signaling Proteins/metabolism , Tumor Microenvironment , Animals , Cell Differentiation , Dendritic Cells/immunology , Homeostasis , Humans , Melanoma/genetics , Melanoma/pathology , Mice , Monocytes/pathology , Sequence Analysis, RNA , Single-Cell Analysis , Skin Neoplasms/genetics , Skin Neoplasms/pathology , TranscriptomeABSTRACT
The most straightforward method to increase monoclonal antibody (mAb) product yield is to complete the purification process in less steps. Here, three different fiber chromatographic devices were implemented using a holistic approach to intensify the mAb purification process and increase yield. Fiber protein A (proA) chromatography was first investigated, but traditional depth filtration was not sufficient in reducing the contaminant load as the fiber proA device prematurely fouled. Further experimentation revealed that chromatin aggregates were the most likely reason for the fiber fouling. To reduce levels of chromatin aggregates, a chromatographic clarification device (CCD) was incorporated into the process, resulting in single-stage clarification of harvested cell culture fluid and reduction of DNA levels. The CCD clarified pool was then successfully processed through the fiber proA device, fully realizing the productivity gains that the fiber technology offers. After the proA and viral inactivation neutralization (VIN) hold step, the purification process was further intensified using a novel single-use fiber-based polishing anion exchange (AEX) material that is capable of binding both soluble and insoluble contaminants. The three-stage fiber chromatographic purification process was compared to a legacy five-step process of dual-stage depth filtration, bead-based proA chromatography, post-VIN depth filtration, and bead-based AEX chromatography. The overall yield from the five-step process was 60%, while the fiber chromatographic-enabled intensified process had an overall yield of 70%. The impurity clearance of DNA and host cell protein (HCP) for both processes were within the regulatory specification (<100 ppm HCP, <1 ppb DNA). For the harvest of a 2000 L cell culture, the intensified process is expected to increase productivity by 2.5-fold at clarification, 50-fold at the proA step, and 1.6-fold in polishing. Relative to the legacy process, the intensified process would reduce buffer use by 1088 L and decrease overall process product mass intensity by 12.6%.
Subject(s)
Antibodies, Monoclonal , Chromatography , Animals , Cricetinae , Antibodies, Monoclonal/chemistry , Cell Culture Techniques , DNA , Chromatin , Staphylococcal Protein A/chemistry , Cricetulus , CHO CellsABSTRACT
BACKGROUND: To explore the use of a thermoreversible copolymer gel coating to prevent donor tissue scrolling in Descemet's membrane endothelial keratoplasty (DMEK). METHODS: PLGA-PEG-PLGA triblock copolymer was synthesised via ring opening polymerisation. Two formulations were fabricated and gelation properties characterised using rheological analyses. Endothelial cytotoxicity of the copolymer was assessed using a Trypan Blue exclusion assay. Thickness of the copolymer gel coating on the endothelial surface was analysed using anterior segment optical coherence tomography (OCT) (RTVue-100, Optovue Inc.). Gold nanoparticles were added to the copolymer to aid visualisation using OCT. Prevention of Descemet membrane donor scrolling was represented via a novel, in vitro, immersion of copolymer coated donor graft material. RESULTS: Two different formulations of PLGA-PEG-PLGA copolymer were successfully fabricated and the desired peak gelling temperature of 24°C was achieved by polymer blending. Application of 20%, 30% and 40% (wt/vol) polymer concentrations resulted in a statistically significant increase in polymer thickness on the endothelium (p < 0.001). There was no detectable endothelial cytotoxicity. The polymer was easy to apply to the endothelium and prevented scrolling of the DMEK graft. CONCLUSION: This PLGA-PEG-PLGA thermoreversible copolymer gel could be exploited as a therapeutic aid for preventing DMEK graft scrolling.
Subject(s)
Descemet Stripping Endothelial Keratoplasty , Metal Nanoparticles , Humans , Descemet Membrane/surgery , Endothelium, Corneal/surgery , Gold , Descemet Stripping Endothelial Keratoplasty/methods , PolymersABSTRACT
The presence of GBA1 gene mutations increases risk for Parkinson's disease (PD), but the pathogenic mechanisms of GBA1 associated PD remain unknown. Given that impaired α-synuclein turnover is a hallmark of PD pathogenesis and cathepsin D is a key enzyme involved in α-synuclein degradation in neuronal cells, we have examined the relationship of glucocerebrosidase (GCase), cathepsin D and monomeric α-synuclein in human neural crest stem cell derived dopaminergic neurons. We found that normal activity of GCase is necessary for cathepsin D to perform its function of monomeric α-synuclein removal from neurons. GBA1 mutations lead to a lower level of cathepsin D protein and activity, and higher level of monomeric α-synuclein in neurons. When GBA1 mutant neurons were treated with GCase replacement or chaperone therapy; cathepsin D protein levels and activity were restored, and monomeric α-synuclein decreased. When cathepsin D was inhibited, GCase replacement failed to reduce monomeric α-synuclein levels in GBA1 mutant neurons. These data indicate that GBA1 gene mutations increase monomeric α-synuclein levels via an effect on lysosomal cathepsin D in neurons.
Subject(s)
Cathepsin D/metabolism , Dopaminergic Neurons/metabolism , Glucosylceramidase/metabolism , Parkinson Disease , alpha-Synuclein/metabolism , Cells, Cultured , Glucosylceramidase/genetics , Humans , Mutation , Neural Crest , Neural Stem Cells , Parkinson Disease/metabolism , Parkinson Disease/pathologySubject(s)
Epstein-Barr Virus Infections , Hodgkin Disease , Immunoconjugates , Lymphoma, Large B-Cell, Diffuse , Brentuximab Vedotin/adverse effects , Epstein-Barr Virus Infections/chemically induced , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/pathology , Herpesvirus 4, Human , Hodgkin Disease/drug therapy , Hodgkin Disease/pathology , Humans , Immunoconjugates/adverse effects , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/pathologySubject(s)
Antineoplastic Agents/pharmacology , Arsenic Trioxide/pharmacology , Lymphoma, Large B-Cell, Diffuse/drug therapy , Oncogene Proteins, Fusion/genetics , Anaplastic Lymphoma Kinase/analysis , Anaplastic Lymphoma Kinase/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Lymphoma, Large B-Cell, Diffuse/genetics , Oncogene Proteins, Fusion/analysisABSTRACT
Tissue engineering is a multidisciplinary field that combines aspects of biology, material sciences, engineering and medicine - the ultimate goal being able to fabricate replacement tissues and/or organs for an ageing population. However, parallel to this milestone, is the exploitation of the biomimetic constructs as feasible alternatives to in vivo/ex vivo toxicity testing models due to their accurate representation of innate tissue and organs. Herein, we summarise a range of concepts within tissue engineering with a particular emphasis on biological material selection and implications to animal testing.
Subject(s)
Tissue Engineering , Toxicity Tests/methods , Animals , HumansABSTRACT
Transglutaminases (TGs) stabilize proteins by the formation of ε(γ-glutamyl)lysine cross-links. Here, we demonstrate that the cross-linking of collagen I (COL I) by tissue transglutaminase (TG2) causes an alteration in the morphology and rheological properties of the collagen fibers. Human osteoblasts (HOB) attach, spread, proliferate, differentiate and mineralize more rapidly on this cross-linked matrix compared to native collagen. When seeded on cross-linked COL I, HOB are more resistant to the loss of cell spreading by incubation with RGD containing peptides and with α1, α2 and ß1 integrin blocking antibodies. Following adhesion on cross-linked collagen, HOB show increased phosphorylation of the focal adhesion kinase, and increased expression of ß1 and ß3 integrins. Addition of human bone morphogenetic protein to HOB seeded on TG2 cross-linked COL I enhanced the expression of the differentiation marker bone alkaline phosphatase when compared to cross-linked collagen alone. In summary, the use of TG2-modified COL I provides a promising new scaffold for promoting bone healing.
Subject(s)
Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Collagen Type I/chemistry , GTP-Binding Proteins/chemistry , Transglutaminases/chemistry , Alkaline Phosphatase/metabolism , Antibodies/pharmacology , Cell Adhesion/drug effects , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Gene Expression Regulation/drug effects , Humans , Integrins/immunology , Materials Testing , Oligopeptides/pharmacology , Osteoblasts/drug effects , Peptides/chemistry , Peptides/pharmacology , Protein Glutamine gamma Glutamyltransferase 2 , Signal Transduction/drug effectsABSTRACT
Here, we announce the complete genome sequence of a Pasteurella multocida isolate (PM1463) obtained from a diseased pig as a part of routine diagnostic investigations by the field veterinarian in Queensland, Australia. The assembly consists of a 2,321,605-bp chromosome and a 4,769-bp plasmid. The assembly has an average GC content of 40.33%.
ABSTRACT
Combinations of different biomaterials with their own advantages as well as functionalization with other components have long been implemented in tissue engineering to improve the performance of the overall material. Biomaterials, particularly hydrogel platforms, have shown great potential for delivering compounds such as drugs, growth factors, and neurotrophic factors, as well as cells, in neural tissue engineering applications. In central the nervous system, astrocyte reactivity and glial scar formation are significant and complex challenges to tackle for neural and functional recovery. GelMA hydrogel-based tissue constructs have been developed in this study and combined with two different formulations of phosphate glass fibers (PGFs) (with Fe3+ or Ti2+ oxide) to impose physical and mechanical cues for modulating astrocyte cell behavior. This study was also aimed at investigating the effects of lithium-loaded GelMA-PGFs hydrogels in alleviating astrocyte reactivity and glial scar formation offering novel perspectives for neural tissue engineering applications. The rationale behind introducing lithium is driven by its long-proven therapeutic benefits in mental disorders, and neuroprotective and pronounced anti-inflammatory properties. The optimal concentrations of lithium and LPS were determined in vitro on primary rat astrocytes. Furthermore, qPCR was conducted for gene expression analysis of GFAP and IL-6 markers on primary astrocytes cultured 3D into GelMA and GelMA-PGFs hydrogels with and without lithium and in vitro stimulated with LPS for astrocyte reactivity. The results suggest that the combination of bioactive phosphate-based glass fibers and lithium loading into GelMA structures may impact GFAP expression and early IL-6 expression. Furthermore, GelMA-PGFs (Fe) constructs have shown improved performance in modulating glial scarring over GFAP regulation.
Subject(s)
Astrocytes , Glass , Lithium , Phosphates , Astrocytes/drug effects , Astrocytes/metabolism , Animals , Glass/chemistry , Phosphates/chemistry , Phosphates/pharmacology , Lithium/pharmacology , Lithium/chemistry , Rats , Hydrogels/chemistry , Hydrogels/pharmacology , Tissue Scaffolds/chemistry , Cells, Cultured , Glial Fibrillary Acidic Protein/metabolismABSTRACT
Many pathological conditions are predominantly associated with oxidative stress, arising from reactive oxygen species (ROS); therefore, the modulation of redox activities has been a key strategy to restore normal tissue functions. Current approaches involve establishing a favorable cellular redox environment through the administration of therapeutic drugs and redox-active nanomaterials (RANs). In particular, RANs not only provide a stable and reliable means of therapeutic delivery but also possess the capacity to finely tune various interconnected components, including radicals, enzymes, proteins, transcription factors, and metabolites. Here, we discuss the roles that engineered RANs play in a spectrum of pathological conditions, such as cancer, neurodegenerative diseases, infections, and inflammation. We visualize the dual functions of RANs as both generator and scavenger of ROS, emphasizing their profound impact on diverse cellular functions. The focus of this review is solely on inorganic redox-active nanomaterials (inorganic RANs). Additionally, we deliberate on the challenges associated with current RANs-based approaches and propose potential research directions for their future clinical translation.
ABSTRACT
Protein-based biomaterial use is expanding within medicine, together with the demand to visualize their placement and behavior in vivo. However, current medical imaging techniques struggle to differentiate between protein-based implants and surrounding tissue. Here a fast, simple, and translational solution for tracking transplanted protein-based scaffolds is presented using X-ray CT-facilitating long-term, non-invasive, and high-resolution imaging. X-ray visible scaffolds are engineered by selectively iodinating tyrosine residues under mild conditions using readily available reagents. To illustrate translatability, a clinically approved hernia repair mesh (based on decellularized porcine dermis) is labeled, preserving morphological and mechanical properties. In a mouse model of mesh implantation, implants retain marked X-ray contrast up to 3 months, together with an unchanged degradation rate and inflammatory response. The technique's compatibility is demonstrated with a range of therapeutically relevant protein formats including bovine, porcine, and jellyfish collagen, as well as silk sutures, enabling a wide range of surgical and regenerative medicine uses. This solution tackles the challenge of visualizing implanted protein-based biomaterials, which conventional imaging methods fail to differentiate from endogenous tissue. This will address previously unanswered questions regarding the accuracy of implantation, degradation rate, migration, and structural integrity, thereby accelerating optimization and safe translation of therapeutic biomaterials.
Subject(s)
Tissue Engineering , Tissue Scaffolds , Mice , Animals , Cattle , Swine , Tissue Scaffolds/chemistry , Tissue Engineering/methods , X-Rays , Halogenation , Biocompatible Materials/chemistryABSTRACT
An ideal wound dressing should create a healing environment that relieves pain, protects against infections, maintains moisture, removes debris, and speeds up wound closure and repair. However, conventional options like gauze often fall short in fulfilling these requirements, especially for chronic or nonhealing wounds. Hence there is a critical need for inventive formulations that offer efficient, cost-effective, and eco-friendly alternatives. This study focuses on assessing the innovative formulation based on a microbial-derived copolymer known as poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB) bioactive glass and graphene particles, and exploring their biological response in vitro and in vivo-to find the best combination that promotes cell adhesion and enhances wound healing. The formulation optimized at concentration of bioactive glass (1 w/w%) and graphene (0.01 w/w%) showed accelerated degradation and enhanced blood vessel formation. Meanwhile biocompatibility was evaluated using murine osteoblasts, human dermal fibroblasts, and standard cell culture assays, demonstrating no adverse effects after 7 days of culture and well-regulated inflammatory kinetics. Whole thickness skin defect using mice indicated the feasibility of the biocomposites for a faster wound closure and reduced inflammation. Overall, this biocomposite appears promising as an ideal wound dressing material and positively influencing wound healing rates.
Subject(s)
Graphite , Wound Healing , Animals , Graphite/chemistry , Graphite/pharmacology , Mice , Humans , Wound Healing/drug effects , Fibroblasts/metabolism , Fibroblasts/cytology , Polyesters/chemistry , Materials Testing , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Glass/chemistry , Osteoblasts/metabolism , Osteoblasts/cytology , RegenerationABSTRACT
The clinical management of wounds is known to be a significant challenge: not only does the dressing need to ensure and provide the appropriate barrier and healing characteristics, but consideration of patient compliance concerning comfort, functionality, and practicality also needs to be included. The poly(3-hydroxybutyrate-co-4-hydroxubutyrate) (P(3HB-co-4HB)) copolymer, isolated from Cupriavidus malaysiensis USM1020 (C. malaysiensis USM1020), was produced in the presence of excess carbon sources (1,4-butanediol and 1,6-hexanediol) using either a shake flask cultivation process or a bioreactor fermentation system. P(3HB-co-4HB) is widely known to be biodegradable and highly biocompatible and contains a tuneable 4HB monomer molar fraction, which is known to affect the final physicochemical properties of the intracellular copolymer. In this paper, we describe not only the fabrication of the polymeric gel but also its optimised profiling using a range of physical and mechanical techniques, i.e., SEM, FTIR, DMA, DSC, and WCA. The further enhancement of the gel through additional functionalisation with sol-gel-derived bioactive glass and liquid-exfoliated graphene was also investigated. The biocompatibility and biological characterisation of the substrates was assessed using murine osteoblasts (MC3T3), human primary dermal fibroblasts (HDFs), human fibroblast (BJ) cells, and standard cell culture assays (i.e., metabolic activity, LDH release, and live/dead staining). In short, P(3HB-co-4HB) was successfully isolated from the bacteria, with the defined physico-chemical profiles dependent on the culture substrate and culturing platform used. The additional enhancement of the copolymer with bioactive glass and/or graphene was also demonstrated by varying the combination loading of the materials, i.e., graphene resulted in an increase in tensile strength (~11 MPa) and the wettability increased following the incorporation of bioactive glass and 0.01 wt% graphene (WCA ~46.3°). No detrimental effects in terms of biocompatibility were noticed during the 7 days of culture in the primary and established cell lines. This study demonstrates the importance of optimising each of the individual components within the biocomposite and their relationship concerning the fine-tuning of the material's properties, thus targeting and impacting the endpoint application.
ABSTRACT
Collagen is the building block for the extracellular matrix in bone, teeth and other fibrous tissues. Osteogenesis imperfecta (OI), or brittle bone disease, is a heritable disorder that results from defective collagen synthesis or metabolism, resulting in bone fragility. The dental manifestation of OI is dentinogenesis imperfecta (DI), a genetic disorder that affects dentin structure and clinical appearance, with a characteristic feature of greyish-brown discolouration. The aim of this study was to conduct a systematic review to identify and/or define any ultrastructural changes in dentinal collagen in DI. Established databases were searched: Cochrane Library, OVID Embase, OVID Medline and PubMed/Medline. Search strategies included: Collagen Ultrastructure, DI and OI. Inclusion criteria were studies written in English, published after 1990, that examined human dental collagen of teeth affected by DI. A Cochrane data extraction form was modified and used for data collection. The final dataset included seventeen studies published from 1993 to 2021. The most prevalent findings on collagen in DI teeth were increased coarse collagen fibres and decreased fibre quantity. Additional findings included changes to fibre orientation (i.e., random to parallel) and differences to the fibre organisation (i.e., regular to irregular). Ultrastructural defects and anomalies included uncoiled collagen fibres and increased D-banding periodicity. Studies in collagen structure in DI reported changes to the surface topography, quantity, organisation and orientation of the fibres. Moreover, ultrastructural defects such as the packing/coiling and D-banding of the fibrils, as well as differences in the presence of other collagens are also noted. Taken together, this study provides an understanding of the changes in collagen and its impact on clinical translation, paving the way for innovative treatments in dental treatment.
ABSTRACT
Chronic wounds affect millions of people annually and have emotional and financial implications in addition to health issues. The current treatment for chronic wounds involves the repeated use of bandages and drugs such as antibiotics over an extended period. A cost-effective and convenient solution for wound healing is the development of drug-incorporated bandages. This study aimed to develop a biocompatible bandage made of drug-incorporated poly (lactic-co-glycolic acid) (PLGA) microparticles (MPs) and eggshell membrane (ESM) for cornea wound healing. ESM has desirable properties for wound healing and can be isolated from eggshells using acetic acid or ethylenediaminetetraacetic acid (EDTA) protocols. Fluorescein isothiocyanate-labelled Bovine Serum Albumin (FITC-BSA) was used as a model drug, and the PLGA MPs were fabricated using a solvent extraction method. The MPs were successfully attached to the fibrous layer of the ESM using NaOH. The surface features of the ESM samples containing MPs were studied using a field emission scanning electron microscope (FESEM) and compared with blank ESM images. The findings indicated that the MPs were attached to the ESM fibres and had similar shapes and sizes as the control MPs. The fibre diameters of the MPs samples were assessed using Fiji-ImageJ software, and no significant changes were observed compared to the blank ESM. The surface roughness, Ra values, of the MPs incorporated ESM samples were evaluated and compared to the blank ESM, and no significant changes were found. Fourier transform infrared (FTIR) spectroscopy was used to analyse the chemical Composition of the bandage, and the spectra showed that the FBM were effectively incorporated into the ESM. The FTIR spectra identified the major peaks of the natural ESM and the PLGA polymer in the bandage. The bandage was transparent but had a reduced visibility in the waterproof test card method. The bandage achieved sustained drug release up to 10 days and was found to be biocompatible and non-toxic in a chorioallantoic membrane (CAM) assay. Overall, the drug-incorporated PLGA MPs-ESM bandage has great potential for treating chronic wounds.
Subject(s)
Biocompatible Materials , Egg Shell , Animals , Humans , Biocompatible Materials/chemistry , Bandages , Wound Healing , Anti-Bacterial Agents/chemistryABSTRACT
Limitations with the majority of bone therapeutic treatments include low availability, ethical constraints and low biological compatibility. Although a number of choice materials have been exploited successfully, there has always been scope for improvement as well as development of the next-generation of materials. Herein, scaffolds - developed from gelatin, chitosan and eggshell membranes - were crosslinked using tannic acid, and further infused with selenium and/or copper substituted hydroxyapatite nanoparticles to generate a novel nanocomposite substrate. FESEM images of the nanocomposite scaffolds revealed the presence of interconnected pores, mostly spread over the whole surface of the scaffold, alongside XRD and FTIR profiling that detailed the formation of hydroxyapatite as a sole phase. Moreover, physical characterisation of the nanocomposite confirmed that the hydroxyapatite particulates and the eggshell membrane fibres were uniformly distributed and contributed to the surface roughness of the scaffold. Biocompatibility and cytotoxicity of the novel constructs were assessed using the mouse-derived osteoblastic cell line, MC3T3-E1, and standard cell culture assays. Metabolic activity assessment (i.e. MTS assay), LDH-release profiles and Live/Dead staining demonstrated good cell adhesion, viability, and proliferation rates. Accordingly, this work summarises the successful development of a novel construct which may be exploited as a clinical/therapeutic treatment for bone repair as well as a possible translational application as a novel biomaterial for the drug development pipeline.
ABSTRACT
Naturally derived materials are often preferred over synthetic materials for biomedical applications due to their innate biological characteristics, relative availability, sustainability, and agreement with conscientious end-users. The chicken eggshell membrane (ESM) is an abundant resource with a defined structural profile, chemical composition, and validated morphological and mechanical characteristics. These unique properties have not only allowed the ESM to be exploited within the food industry but has also led to it be considered for other novel translational applications such as tissue regeneration and replacement, wound healing and drug delivery. However, challenges still exist in order to enhance the native ESM (nESM): the need to improve its mechanical properties, the ability to combine/join fragments of ESM together, and the addition or incorporation of drugs/growth factors to advance its therapeutic capacity. This review article provides a succinct background to the nESM, its extraction, isolation, and consequent physical, mechanical and biological characterisation including possible approaches to enhancement. Moreover, it also highlights current applications of the ESM in regenerative medicine and hints at future novel applications in which this novel biomaterial could be exploited to beneficial use.
Subject(s)
Chickens , Egg Shell , Animals , Egg Shell/chemistry , Biocompatible Materials/chemistry , Regenerative Medicine , Drug Delivery SystemsABSTRACT
Approximately half of an adult human's body weight is made up of muscles. Thus, restoring the functionality and aesthetics of lost muscle tissue is critical. The body is usually able to repair minor muscle injuries. However, when volumetric muscle loss occurs due to tumour extraction, for instance, the body will form fibrous tissue instead. Gelatin methacryloyl (GelMA) hydrogels have been applied for drug delivery, tissue adhesive, and various tissue engineering applications due to their tuneable mechanical properties. Here, we have synthesised GelMA from different gelatin sources (i.e., porcine, bovine, and fish) with varying bloom numbers, which refers to the gel strength, and investigated for the influence of the source of gelatin and the bloom number on biological activities and mechanical properties. The results indicated that the source of the gelatin and variable bloom numbers have an impact on GelMA hydrogel properties. Furthermore, our findings established that the bovine-derived gelatin methacryloyl (B-GelMA) has better mechanical properties than the other varieties composed of porcine and fish with 60 kPa, 40 kPa, and 10 kPa in bovine, porcine, and fish, respectively. Additionally, it showed a noticeably greater swelling ratio (SR) ~1100% and a reduced rate of degradation, improving the stability of hydrogels and giving cells adequate time to divide and proliferate to compensate for muscle loss. Furthermore, the bloom number of gelatin was also proven to influence the mechanical properties of GelMA. Interestingly, although GelMA made of fish had the lowest mechanical strength and gel stability, it demonstrated excellent biological properties. Overall, the results emphasise the importance of gelatin source and bloom number, allowing GelMA hydrogels to have a wide range of mechanical and excellent biological properties and making them suitable for various muscle tissue regeneration applications.
Subject(s)
Gelatin , Hydrogels , Animals , Cattle , Humans , Swine , Gelatin/pharmacology , Hydrogels/pharmacology , Tissue Engineering/methods , Fishes , MusclesABSTRACT
Atomic substitution or doping of a bioceramic material hydroxyapatite (HA) with specific ions is an appealing approach for improving its biocompatibility and activity, as well as imparting antibacterial properties. In this study, selenium- and/or copper-substituted hydroxyapatite powders were synthesized by an aqueous precipitation method and using the freeze-drying technique. The molar concentrations of constituents were calculated based on the proposed mechanism whereby selenium (Se4+) ions partially substitute phosphorus (P5+) sites, and copper (Cu2+) ions partially substitute (Ca2+) sites in the HA lattice. Dried precipitated samples were characterized using Inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR) and Field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). Accordingly, substitution of Se4+ and/or Cu2+ ions took place in the crystal lattice of HA without the formation of any impurities. The presence of sulphur (S2-) ions in the hydroxyapatite was detected by ICP-OES in all samples with copper substituted in the lattice. The cytotoxicity of the powders on osteoblastic (MC3T3-E1) cells was evaluated in vitro. Selenium substituted hydroxyapatite (SeHA), at the concentration (200 µg/mL), demonstrated higher populations of the live cells than that of control (cells without powders), suggesting that selenium may stimulate the proliferation of these cells. In addition, the copper substituted hydroxyapatite (CuHA) and the selenium and copper substituted hydroxyapatite (SeCuHA) at the concentrations (200 and 300 µg/mL) and (200 µg/mL), respectively demonstrated better results than the unsubstituted HA. Antimicrobial activity was assessed using a well-diffusion method against Streptococcus mutans and Candida albicans, and superior results has obtained with SeCuHA samples. Presented findings imply that selenium and/or copper substituted modified hydroxyapatite nanoparticles, may be an attractive antimicrobial and cytocompatible substrate to be considered for use in a range of translational applications.