Piezoelectric nanogenerators from sustainable biowaste source: Power harvesting and respiratory monitoring with electrospun crab shell powder-poly(vinylidene fluoride) composite nanofibers.

Wearable piezoelectric nanogenerators (PENGs) are increasingly significant in healthcare and energy harvesting applications due to their ability to convert mechanical energy into electrical signals. In this study, we developed PENGs by incorporating crab shell powder (CS-NFs) into electrospun polyvinylidene fluoride (PVDF) nanofibers to enhance their piezoelectric properties. The PVDF-CS-NFs (PC-NFs) composites were evaluated for structural, thermal, and piezoelectric performance.

Multi-objective property optimisation of a phosphoserine-modified calcium phosphate cement for orthopaedic and dental applications using design of experiments methodology.

Phosphoserine is a ubiquitous molecule found in numerous proteins and, when combined with alpha-tricalcium phosphate (α-TCP) powder, demonstrates the ability to generate an adhesive biomaterial capable of stabilising and repairing bone fractures. Design of Experiments (DoE) approach was able to optimise the composition of phosphoserine-modified calcium phosphate cement (PM-CPC) demonstrating that the liquid:powder ratio (LPR) and quantity of phosphoserine (wt%) significantly influenced the handling, mechanical, and adhesion properties. Subsequently, the DoE optimisation process identified the optimal PM-CPC formulation, exhibiting a compressive strength of 29.

Evaluation of a co-culture of rapidly isolated chondrocytes and stem cells seeded on tri-layered collagen-based scaffolds in a caprine osteochondral defect model.

Cartilage has poor regenerative capacity and thus damage to the joint surfaces presents a major clinical challenge. Recent research has focussed on the development of tissue-engineered and cell-based approaches for the treatment of cartilage and osteochondral injuries, with current clinically available cell-based approaches including autologous chondrocyte implantation and matrix-assisted autologous chondrocyte implantation. However, these approaches have significant disadvantages due to the requirement for a two-stage surgical procedure and an in vitro chondrocyte expansion phase which increases logistical challenges, hospital times and costs.

Metallic Microneedles for Transdermal Drug Delivery: Applications, Fabrication Techniques and the Effect of Geometrical Characteristics.

Current procedures for transdermal drug delivery (TDD) have associated limitations including poor administration of nucleic acid, small or large drug molecules, pain and stress for needle phobic people. A painless micro-sized device capable of delivering drugs easily and efficiently, eliminating the disadvantages of traditional systems, has yet to be developed. While polymeric-based microneedle (MN) arrays have been used successfully and clinically as TDD systems, these devices lack mechanical integrity, piercing capacity and the ability to achieve tailored drug release into the systemic circulation.

The Role of Machine Learning and Design of Experiments in the Advancement of Biomaterial and Tissue Engineering Research.

Optimisation of tissue engineering (TE) processes requires models that can identify relationships between the parameters to be optimised and predict structural and performance outcomes from both physical and chemical processes. Currently, Design of Experiments (DoE) methods are commonly used for optimisation purposes in addition to playing an important role in statistical quality control and systematic randomisation for experiment planning. DoE is only used for the analysis and optimisation of quantitative data (i.

Development and characterisation of 3D collagen-gelatin based scaffolds for breast cancer research.

While 2D culture presents a useful tool for cancer research, it fails to replicate the tumor microenvironment as it lacks proper three-dimensional cell-cell/cell-matrix interactions, often resulting in exaggerated responses to therapeutic agents. 3D models that aim to overcome the issues associated with 2D culture research offer a new frontier for cancer research with cell growth, morphology and genetic properties that more closely match in vivo cancers. Herein, we aim to develop a collagen-based scaffold that supports the attachment and proliferation of breast cancer (BC) cells as a 3D culture model.

Biodegradable and Biocompatible Adhesives for the Effective Stabilisation, Repair and Regeneration of Bone.

Bone defects and complex fractures present significant challenges for orthopaedic surgeons. Current surgical procedures involve the reconstruction and mechanical stabilisation of complex fractures using metal hardware (i.e.

Advancing bone tissue engineering one layer at a time: a layer-by-layer assembly approach to 3D bone scaffold materials.

The layer-by-layer (LbL) assembly technique has shown excellent potential in tissue engineering applications. The technique is mainly based on electrostatic attraction and involves the sequential adsorption of oppositely charged electrolyte complexes onto a substrate, resulting in uniform single layers that can be rapidly deposited to form nanolayer films. LbL has attracted significant attention as a coating technique due to it being a convenient and affordable fabrication method capable of achieving a wide range of biomaterial coatings while keeping the main biofunctionality of the substrate materials.

Layer-specific stem cell differentiation in tri-layered tissue engineering biomaterials: Towards development of a single-stage cell-based approach for osteochondral defect repair.

Successful repair of osteochondral defects is challenging, due in part to their complex gradient nature. Tissue engineering approaches have shown promise with the development of layered scaffolds that aim to promote cartilage and bone regeneration within the defect. The clinical potential of implanting these scaffolds cell-free has been demonstrated, whereby cells from the host bone marrow MSCs infiltrate the scaffolds and promote cartilage and bone regeneration within the required regions of the defect.

Translational Application of 3D Bioprinting for Cartilage Tissue Engineering.

Cartilage is an avascular tissue with extremely limited self-regeneration capabilities. At present, there are no existing treatments that effectively stop the deterioration of cartilage or reverse its effects; current treatments merely relieve its symptoms and surgical intervention is required when the condition aggravates. Thus, cartilage damage remains an ongoing challenge in orthopaedics with an urgent need for improved treatment options.

Advances in biofabrication techniques for collagen-based 3D in vitro culture models for breast cancer research.

Collagen is the most abundant component of the extracellular matrix (ECM), therefore it represents an ideal biomaterial for the culture of a variety of cell types. Recently, collagen-based scaffolds have shown promise as 3D culture platforms for breast cancer-based research. Two-dimensional (2D) in vitro culture models, while useful for gaining preliminary insights, are ultimately flawed as they do not adequately replicate the tumour microenvironment.

Hydroxyapatite sonosensitization of ultrasound-triggered, thermally responsive hydrogels: An on-demand delivery system for bone repair applications.

While bones have the innate capability to physiologically regenerate, in certain cases regeneration is suboptimal, too slow, or does not occur. Biomaterials-based growth factor delivery systems have shown potential for the treatment of challenging bone defects, however, achieving controlled growth factor release remains a challenge. The objective of this study was to develop a thermally responsive hydrogel for bone regeneration capable of ultrasound-triggered on-demand delivery of therapeutic agents.

Calcium Phosphate Nanoparticles-Based Systems for RNAi Delivery: Applications in Bone Tissue Regeneration.

Bone-related injury and disease constitute a significant global burden both socially and economically. Current treatments have many limitations and thus the development of new approaches for bone-related conditions is imperative. Gene therapy is an emerging approach for effective bone repair and regeneration, with notable interest in the use of RNA interference (RNAi) systems to regulate gene expression in the bone microenvironment.

Calcium Phosphate Nanoparticles for Therapeutic Applications in Bone Regeneration.

Bone injuries and diseases constitute a burden both socially and economically, as the consequences of a lack of effective treatments affect both the patients' quality of life and the costs on the health systems. This impended need has led the research community's efforts to establish efficacious bone tissue engineering solutions. There has been a recent focus on the use of biomaterial-based nanoparticles for the delivery of therapeutic factors.

Tissue-specific extracellular matrix scaffolds for the regeneration of spatially complex musculoskeletal tissues.

Biological scaffolds generated from tissue-derived extracellular matrix (ECM) are commonly used clinically for soft tissue regeneration. Such biomaterials can enhance tissue-specific differentiation of adult stem cells, suggesting that structuring different ECMs into multi-layered scaffolds can form the basis of new strategies for regenerating damaged interfacial tissues such as the osteochondral unit. In this study, mass spectrometry is used to demonstrate that growth plate (GP) and articular cartilage (AC) ECMs contain a unique array of regulatory proteins that may be particularly suited to bone and cartilage repair respectively.

Freeze-Drying as a Novel Biofabrication Method for Achieving a Controlled Microarchitecture within Large, Complex Natural Biomaterial Scaffolds.

The biofabrication of large natural biomaterial scaffolds into complex 3D shapes which have a controlled microarchitecture remains a major challenge. Freeze-drying (or lyophilization) is a technique used to generate scaffolds in planar 3D geometries. Here we report the development of a new biofabrication process to form a collagen-based scaffold into a large, complex geometry which has a large height to width ratio, and a controlled porous microarchitecture.

Repair of large osteochondritis dissecans lesions using a novel multilayered tissue engineered construct in an equine athlete.

Osteochondral lesions resulting from osteochondritis dissecans are problematic to treat and present a significant challenge for clinicians. The aims of this study were to investigate the use of a scaffold-assisted microfracture approach, employing a novel, multilayered, collagen-based, osteochondral graft substitute in the treatment of severe osteochondritis dissecans of both lateral femoral trochlear ridges in an equine athlete, and to assess the potential of this novel scaffold to enhance repair of the osteochondral unit. A 15 month-old female filly presented with large osteochondritis dissecans lesions involving both femoral lateral trochlear ridges.

The benefits and limitations of animal models for translational research in cartilage repair.

Much research is currently ongoing into new therapies for cartilage defect repair with new biomaterials frequently appearing which purport to have significant regenerative capacity. These biomaterials may be classified as medical devices, and as such must undergo rigorous testing before they are implanted in humans. A large part of this testing involves in vitro trials and biomechanical testing.

Cell-free multi-layered collagen-based scaffolds demonstrate layer specific regeneration of functional osteochondral tissue in caprine joints.

Developing repair strategies for osteochondral tissue presents complex challenges due to its interfacial nature and complex zonal structure, consisting of subchondral bone, intermediate calcified cartilage and the superficial cartilage regions. In this study, the long term ability of a multi-layered biomimetic collagen-based scaffold to repair osteochondral defects is investigated in a large animal model: namely critical sized lateral trochlear ridge (TR) and medial femoral condyle (MC) defects in the caprine stifle joint. The study thus presents the first data in a clinically applicable large animal model.

Multi-layered collagen-based scaffolds for osteochondral defect repair in rabbits.

Introduction: Identification of a suitable treatment for osteochondral repair presents a major challenge due to existing limitations and an urgent clinical need remains for an off-the-shelf, low cost, one-step approach. A biomimetic approach, where the biomaterial itself encourages cellular infiltration from the underlying bone marrow and provides physical and chemical cues to direct these cells to regenerate the damaged tissue, provides a potential solution. To meet this need, a multi-layer collagen-based osteochondral defect repair scaffold has been developed in our group.

Platelet-rich plasma releasate differently stimulates cellular commitment toward the chondrogenic lineage according to concentration.

Platelet-rich plasma has been used to treat articular cartilage defects, with the expectations of anabolic and anti-inflammatory effects. However, its role on cellular chondrogenic or fibrogenic commitment is still a controversy. Herein, the role of platelet-rich plasma releasate, the product obtained following platelet-rich plasma activation, on cellular commitment toward the chondrogenic lineage was evaluated in vitro.

Incorporation of fibrin into a collagen-glycosaminoglycan matrix results in a scaffold with improved mechanical properties and enhanced capacity to resist cell-mediated contraction.

Unlabelled: Fibrin has many uses as a tissue engineering scaffold, however many in vivo studies have shown a reduction in function resulting from the susceptibility of fibrin to cell-mediated contraction. The overall aim of the present study was to develop and characterise a reinforced natural scaffold using fibrin, collagen and glycosaminoglycan (FCG), and to examine the cell-mediated contraction of this scaffold in comparison to fibrin gels. Through the use of an injection loading technique, a homogenous FCG scaffold was developed.

Incorporation of TGF-beta 3 within collagen-hyaluronic acid scaffolds improves their chondrogenic potential.

Incorporation of therapeutics in the form of growth factors within biomaterials can enhance their biofunctionality. Two methods of incorporating transforming growth factor-beta 3 within collagen-hyaluronic acid scaffolds are described, markedly improving mesenchymal stem cell-mediated chondrogenic differentiation and matrix production. Such scaffolds offer control over the release of therapeutics, demonstrating their potential for repair of complex chondral defects requiring additional stimuli.

Enhanced bone healing using collagen-hydroxyapatite scaffold implantation in the treatment of a large multiloculated mandibular aneurysmal bone cyst in a thoroughbred filly.

An unmet need remains for a bone graft substitute material that is biocompatible, biodegradable and capable of promoting osteogenesis safely in vivo. The aim of this study was to investigate the use of a novel collagen-hydroxyapatite (CHA) bone graft substitute in the clinical treatment of a mandibular bone cyst in a young horse and to assess its potential to enhance repair of the affected bone. A 2 year-old thoroughbred filly, presenting with a multilobulated aneurysmal bone cyst, was treated using the CHA scaffold.

In vitro fibroblast and pre-osteoblastic cellular responses on laser surface modified Ti-6Al-4V.

The success of any implant, dental or orthopaedic, is driven by the interaction of implant material with the surrounding tissue. In this context, the nature of the implant surface plays a direct role in determining the long term stability as physico-chemical properties of the surface affect cellular attachment, expression of proteins, and finally osseointegration. Thus to enhance the degree of integration of the implant into the host tissue, various surface modification techniques are employed.