Biomedical Applications Research Articles

Electrospun silk for biomedical applications

AbstractElectrospinning technology, capable of creating nanofiber-based materials with large specific surface areas and exceptional breathability, has become an important tool in the biomedical field. Silk, as a well-known natural biopolymer, features good biocompatibility, customizable biodegradability, and superior mechanical properties. The conversion of silk into nanofibers via electrospinning allows for the fine-tuning of its properties, thereby enhancing its suitability for a variety of biomedical applications. Electrospun silk not only inherits the natural advantages of silk but also acquires optimized characteristics such as increased surface area, high porosity, and good air permeability. This review article begins by summarizing the latest advances in the rational design and controlled fabrication of electrospun silk. Then, the biomedical applications of electrospun silk in three main areas: health monitoring, regenerative medicine, and personal protection, are reviewed. Lastly, the existing challenges and future perspectives of electrospun silk are discussed. This review aims to highlight the cutting-edge role of electrospun silk in biomedical applications, potentially revolutionizing traditional healthcare into a personalized model. Graphical Abstract

Programming the Dynamic Range of Nanochannel Biosensors for MicroRNA Detection Through Allosteric DNA Probes

AbstractSolid‐state nanochannel biosensors are extensively utilized for microRNA (miRNA) detection owing to their high sensitivity and rapid response. However, conventional nanochannel biosensors face limitations in their fixed dynamic range, restricting their versatility and efficacy. Herein, we introduce tunable triblock DNA probes with varying affinities for target miRNA to engineer solid‐state nanochannel biosensors capable of customizable dynamic range adjustment. The triblock DNA architecture comprises a poly‐adenine (polyA) block for adjustable surface density anchoring, alongside stem and loop blocks for modulating structural stability. Through systematic manipulation of these blocks, we demonstrate the ability to achieve diverse target binding affinities and detection limits, achieving an initial 81‐fold dynamic range. By combining probes with various affinities, we extend this dynamic range significantly to 10,900‐fold. Furthermore, by implementing a sequestration mechanism, the effective dynamic range of the nanochannel biosensor is narrowed to only a 3‐fold span of target concentrations. The customizable dynamic range of these advanced nanochannel biosensors makes them highly promising for a broad spectrum of biomedical and clinical applications.

Micro- and Nanostructured Biomaterials for Biomedical Applications and Regenerative Medicine

Over the past two decades, research on innovative micro- and nano-biomaterials has seen a significant surge in the bioengineering, biomedicine, and regenerative medicine fields [...]

Comprehensive review of biological response, alloy design, strengthening mechanisms, performance evaluation, and surface modifications of titanium alloys for biomedical applications

Comprehensive review of biological response, alloy design, strengthening mechanisms, performance evaluation, and surface modifications of titanium alloys for biomedical applications

Sea food by-products valorization for biomedical applications: evaluation of their wound regeneration capabilities in an Ex vivo skin model

IntroductionThe skin is often exposed to harmful stimuli that might compromise its integrity and functionality. After an injury, the skin has a limited capability to restore its complex structure, and in the case of severe skin damage, surgical operations and rapid application of wound dressings are often required to promote optimal wound healing. Nowadays, collagen-based biomaterials are widely used in combination with bioactive molecules able to prevent excessive inflammation and possible infections. In line with a circular economy and blue biotechnology approach, it was recently demonstrated that both collagen and bioactive molecules (i.e., antioxidant compounds) can be sustainably obtained from sea food by-products and effectively used for biomaterial development. Herein, we describe and compare the application of two marine collagen-based wound dressings (CBWDs), produced with materials obtained from sea urchin food waste, for the treatment of skin lesions in a wound healing organ culture (WHOC) model.MethodsThe ex vivo WHOC model was set up starting from rat skin explants and the induced lesions were assigned into three different groups: control (CTRL) group, not treated, marine collagen wound dressing (MCWD) group, and antioxidants-enriched marine collagen wound dressing (A-MCWD) group. After 5 and 10 days, specimens were examined for organ maintenance and assessed for the healing process.ResultsImmunohistochemical results showed that both CBWDs were similarly successful in prolonging skin repair, preserving the epidermal barrier up to 5 days under static culture conditions. Histological and gene expression analysis highlighted that the A-MCWD might support and accelerate skin wound healing by exerting antioxidant activity and counteracting inflammation.DiscussionOverall, these findings underline the potential of sea urchin food waste as a novel resource for the development of functional medical devices for the treatment of skin wounds.

Spherical Shell Bioprinting to Produce Uniform Spheroids with Controlled Sizes

Conventional cell spheroid production methods are largely manual, leading to variations in size and shape that compromise consistency and reliability for use in cell-based therapeutic applications. To enhance spheroid production, a spherical shell bioprinting system was implemented, enabling the high-throughput generation of uniform cell spheroids with precisely controlled sizes. The system encapsulates cells within thin alginate hydrogel shells formed through bioprinting and ion crosslinking reactions. Alginate–calcium ion crosslinking created alginate shells that contained gelatin-based bioinks with embedded cells, facilitating spontaneous cell aggregation within the shells and eliminating the need for plastic wells. By adjusting cell concentrations in the alginate–gelatin bioink, we achieved precise control over spheroid size, maintaining a sphericity above 0.94 and size deviations within ±10 µm. This method has been successfully applied to various cell types including cancer cells, fibroblasts, chondrocytes, and epithelial cells, demonstrating its versatility. This scalable approach enhances the reliability of cell therapy and drug screening, offering a robust platform for future biomedical applications.

Antibacterial, Antioxidant and Cytotoxicity Assessment of Crassocephalum crepidioides Leaf Extract

The goal of the present investigation was to demonstrate the antibacterial activity of different solvent extracts (methanol, ethanol, cold aqueous and hot aqueous) of Crassocephalum crepidioides against ATCC bacterial cultures of Staphylococcus aureus, Escherichia coli, Methicillin resistant Staphylococcus aureus, Pseudomonas aeruginosa and its antioxidant potential. Furthermore, the chemical constituents present in the extract was perused by Gas chromatography-mass spectroscopy (GC-MS), along with in vitro cytotoxicity assessment. All the extracts were shown to be sensitive against S. aureus, MRSA and P. aeruginosa except for the ethanolic extract which was resistant to P. aeruginosa. Of all the extracts, hot aqueous extract found to be the most effective. It was found that Minimum inhibitory concentration (MIC) value of hot aqueous extract against S. aureus, MRSA and P. aeruginosa were 5 mg/mL, 5 mg/mL and 40 mg/mL, respectively. DPPH results showed that C. crepidioides leaf extract has potent antioxidant activity with IC50 value of 57.9 µg/mL. 22 compounds were detected in hot aqueous extract through Gas chromatography-mass spectroscopy. The results of the cytotoxicity evaluation displayed that the IC50 value of the hot aqueous extract of C. crepidioides on Vero cell lines was 292 µg/mL. This study concludes that C. crepidioides leaf extract is non-toxic, has various bioactive components and strong antibacterial and antioxidant activities, thus making it a promising therapeutic agent for various biomedical applications.

Improving the Cellular Internalization of Zr(IV) Nanocages by Tuning Hydrophilicity and Lipophilicity

AbstractNanoscale molecular materials have emerged as a new class of compounds at the nanometer scale with well‐defined chemical structures, remarkable uniformity and high reproducibility. Among these materials, zirconium‐based metal‐organic cages (MOCs) have attracted significant attention due to their exceptional stability and applications in catalysis, recognition and separation and so on. However, their poor water solubility impedes their biomedical applications. In this study, decorating the ligand with Ru(II) complexes can not only improve the water solubility but also endow bright red fluorescence with large Stokes shift (180 nm). Notably, butyl‐modification of the cyclopentadiene rings can significantly enhance the cell uptake (100 folds) of nanocages via actin‐ and dynamin‐mediated endocytosis. The unique advantages and easy modifiability of these nanocages make them highly promising candidates for diverse biological applications.

Insights on bio-medical, quantum, and optoelectronic applications of 2D transition metal dichalcogenides–a review

Insights on bio-medical, quantum, and optoelectronic applications of 2D transition metal dichalcogenides–a review

Probing the Interplay of Protein Self-Assembly and Covalent Bond Formation in Photo-Crosslinked Silk Fibroin Hydrogels.

Covalent crosslinking of silk fibroin via native tyrosine residues has been extensively explored; however, while these materials are very promising for biomedical, optical, soft robotics, and sensor applications, their structure and mechanical properties are unstable over time. This instability results in spontaneous silk self-assembly and stiffening over time, a process that is poorly understood. This study investigates the interplay between self-assembly and di-tyrosine bond formation in silk hydrogels photo-crosslinked using ruthenium (Ru) and sodium persulfate (SPS) with visible light. The effects of silk concentration, molecular weight, Ru/SPS concentration, and solvent conditions are examined. The Ru/SPS system enables rapid crosslinking, achieving gelation within seconds and incorporating over 90% of silk into the network, even at very low protein concentrations (≥0.75%wt/v). A model emerges where silk self-assembly both before and after crosslinking affects protein phase separation, mesoscale structure, and dynamic changes in the hydrogel network over time. Silk concentration has the greatest impact on hydrogel properties, with higher silk concentration hydrogels experiencing two orders of magnitude increase in stiffness within 1 week. This new understanding and ability to tune hydrogel properties and dynamic stiffening aids in developing advanced materials for 4D biofabrication, sensing, 3D cancer models, drug delivery, and soft robotics.

Thermally Induced Gelling Systems Based on Patchy Polymeric Micelles

AbstractThermogels that exhibit a sol‐gel transition at body temperature represent a promising class of injectable biomaterials for biomedical applications. Thermogels reported thus far are generally composed of amphiphilic block copolymer micelles with an isotropic thermosensitive surface that induces intermicellar aggregation upon heating. Despite the promise, these hydrogels exhibit low mechanical strengths due to their uncontrollable aggregation resulting in void formation. To gain better control over intermicellar assembly, herein a novel thermogel design concept is presented based on patchy polymeric micelles bearing multiple thermosensitive surface domains. These domains serve as “patches” to bridge the micelles to form a percolated network structure. Patchy micelles are prepared from a binary mixture of amphiphilic block copolymers: Poly(N‐acryloylmorpholine)‐b‐poly(N‐benzylacrylamide) (PAM‐PBzAM) and poly (N‐isopropyl acrylamide)‐b‐poly(N‐benzylacrylamide) (PNIPAM‐PBzAM), where PBzAM, PAM and PNIPAM are the hydrophobic, hydrophilic and thermosensitive blocks, respectively. At 25 °C, the polymers self‐assembled into mixed shell micelles having a phase‐separated shell with PAM‐ and PNIPAM‐rich domains. At 37 °C, the PNIPAM domains undergo a hydrophilic‐to‐hydrophobic transition to induce intermicellar assembly into entangled worm‐like structures resulting in hydrogel formation. Patchy micelles form a homogeneous network structure without voids. The micelle design significantly affects the inter‐micellar assembly, the thermogelling behavior, and the mechanical properties of the hydrogels.

Synthesis of chitosan nanoparticles (CSNP): effect of CH-CH-TPP ratio on size and stability of NPs

In the face of a pressing global issue-the escalating threat of antibiotic resistance-the development of new antimicrobial agents is urgent. Nanotechnology, with its innovative approach, emerges as a promising solution to enhance the efficacy of these agents and combat the challenge of microbial resistance. Chitosan nanoparticles (CSNPs) stand out in biomedical applications, particularly in the controlled release of antibiotics, with their unique properties such as biocompatibility, stability, biodegradability, non-toxicity, and simple synthesis processes suitable for sensitive molecules. This study synthesized CSNPs using the ionotropic gelation method, with tripolyphosphate (TPP) as the crosslinking agent. Various CS: TPP ratios (6:1, 5:1, 4:1, 3:1, 2:1) were tested, and the resulting nanoparticles were evaluated using dynamic light scattering (DLS). The CS: TPP ratio of 4:1, with an average hydrodynamic diameter (DHP) of (195 ± 10) nm and a zeta potential of (51 ± 1) mV, was identified as the most suitable for further analysis. The characterization of NPs by Transmission Electron Microscope (TEM) and atomic force microscopy (AFM) revealed diameters of (65 ± 14) nm and (102 ± 18) nm, respectively. Notably, CSNPs exhibited significant aggregation during centrifugation and lyophilization, leading to diameter increases of up to 285% as measured by AFM. The antibacterial activity of CSNPs against Staphylococcus aureus and Escherichia coli was assessed using the resazurin assay. It was found that CSNPs not subjected to centrifugation, freezing, and lyophilization retained their antimicrobial activity. In contrast, those that underwent these processes lost their efficacy, likely due to aggregation and destabilization of the system. This study presents a straightforward and effective protocol for encapsulating sensitive active agents and synthesizing chitosan nanoparticles, a potential system with significant implications in the fight against antibiotic resistance.

Interfacing Complex Coacervates with Natural Cells

Coacervates have been investigated as protocells or synthetic cells, as well as subcellular compartments for the creation of new materials, thus bridging the gap between living and non‐living systems in materials science, synthetic biology, and bioengineering. Given the design flexibility and simplicity of coacervates, along with the functionality and complexity of natural cells, the interfacing of complex coacervates with natural cells is considered significant for various biotechnological and biomedical applications. In this review, the fundamental mechanisms and underlying theories of coacervate systems are introduced. Recent efforts to interface coacervates with natural cells are summarized in three key scenarios: (i) the integration of coacervates with natural cell components for the living material assembly into protocells; (ii) communication between therapeutic synthetic cells and natural cells for drug delivery and cell repair; and (iii) the formation of intracellular condensates for metabolic regulation, followed by the regulation of their phase transitions for pathological elucidation. Finally, the potential of coacervate‐natural cell interfaces is discussed in the context of developing living/synthetic cell constructs, creating precise disease therapy strategies, and advancing programmable metabolic engineering networks.

Reduced Graphene Oxide-Based Flexible Pressure Sensor for Biomedical Applications

Reduced Graphene Oxide-Based Flexible Pressure Sensor for Biomedical Applications

Additively manufactured microwave sensor for glucose level detection in saliva.

In this paper, a novel realization of an ink-on-glass microwave sensor for biomedical applications is proposed. The Aerosol Jet Printing (AJP) technology is leveraged to implement a compact single-layer coplanar waveguide sensor featuring arc-shaped interdigital fingers that can accommodate a droplet of the Material-Under-Test (MUT). Such geometry provides a high sensitivity to even a very small deviation of MUT`s electrical properties when placed as a superstrate. An application towards the detection of trace amounts of glucose in saliva, which is a biomarker for diabetes, is showcased. The design and fabrication process of an exemplary sensor is discussed in detail. A circular geometry feature is introduced that helps a droplet to lie over the sensitive region due to wettability difference of glass substrate and silver ink. Sensor operating in K-band is developed providing a tradeoff between circuit size and droplet volume. The study is conducted for an artificial saliva requiring roughly a 0.5 µL droplet where changes in mixture content are proportional to relative changes of sensor`s transmission coefficient in a broad frequency range for occupied vs. empty states. The obtained results show that 10mg of glucose per 100ml of saliva can be easily distinguished in a frequency range of 20-30GHz, whereas a monotonical change is visible for frequencies 20-26GHz, which indicates the applicability of this sensor towards the detection of saliva-glucose levels and potential application in the detection of small amounts of other substances in liquids.

Bimodal Visual Sensors Based on Mechanoluminescence and Biosensing for Artificial Intelligence‐Assisted Orthodontics

AbstractFlexible visual sensors hold great potential for application in wearable electronics and health monitoring. However, the separate acquisition of various visual signals without mutual interference and their functional integration in internal biomedical devices remains a significant challenge. Here, a functional material that integrates mechanoluminescent units with biosensing units through supramolecular interactions, enabling bimodal non‐interfering visual detection of orthodontic force and bacterial infection is presented. The orthodontic force induces fluorescence by facilitating the release of electrons from trapped energy levels, caused by the disruption or rearrangement of defect structures within strontium aluminate crystals. Meanwhile, the seamlessly integrated biosensing component can effectively detect lactic acid in a dose‐dependent manner, underscoring its multifunctional capabilities in biosensing applications. Moreover, the development of a cloud‐based deep learning server can achieve a 97.7% accuracy in the precise decoupling of visual signals, facilitating remote monitoring and enabling early intervention during orthodontic treatment. The proposed artificial intelligence‐enhanced bimodal visual sensors represent a new paradigm for orthodontic monitoring, suitable for a wide range of biomedical applications.

Influence of material orientation, loading angle, and single-shot repetition of laser shock peening on surface roughness properties

Titanium alloy Ti6Al4V is extensively utilized in biomedical applications due to its excellent biocompatibility, corrosion resistance, and mechanical properties. The design of dental implant surface textures has changed throughout time to address issues with oral rehabilitation in both healthy and damaged bones. The longevity of an implant is significantly impacted by surface roughness. This study examines the use of laser shock peening (LSP) as a surface modification technique to improve the mechanical properties of implants. A numerical model is developed using the commercial finite elements software in ABAQUS/Explicit for simulating dynamic conditions. The aim of the study is to develop surface roughness parameters using computational methods such as studies have not yet been contemplated. The single shot angle, shot repeat, time, material orientation, and laser power are applied for the first time simultaneously to evaluate the impact of material orientation and loading angles on surface roughness parameters. The study showed that the developed computational model’s compressive residual stress was −578.45 MPa, while the experimental samples were −592.18 MPa. Consequently, the difference between the computational and experimental results was 2.32%. Without regard to material orientation or angle, the compressive residual stress of the samples under examination was found to be −578.450 MPa after three repetitions and to decreased to −1.620 MPa after four. These results demonstrate that by varying the material orientation and loading angle, the Ra value may be increased four times.

Designing Antibacterial-Based Quaternary Ammonium Coatings (Surfaces) or Films for Biomedical Applications: Recent Advances

Antibacterial coatings based on quaternary ammonium compounds (QACs) have been widely investigated in controlled release applications. Quaternary ammonium compounds are low-cost and easily accessible disinfectants that have been extensively used, especially after the COVID-19 outbreak. There has been a growing interest in developing a clearer understanding of various aspects that need to be taken into account for the design of quaternary ammonium compounds to be used in the biomedical field. In this contribution, we outline the mechanism of action of those materials as well as the key design parameters associated with their structure and antibacterial activity. Moreover, emphasis has been placed on the type of antibacterial coatings based on QACs and their applications in the biomedical field. A brief outlook on future research guidelines for the development of dual-function antibacterial coatings is also discussed.

A review on exploring the potential of PVA and chitosan in biomedical applications: A focus on tissue engineering, drug delivery and biomedical sensors.

Polymers have been integral to the advancement of biomedicine, owing to their exceptional versatility and functionality. Among these, polyvinyl alcohol (PVA) and chitosan both natural polymers stand out for their remarkable biocompatibility, biodegradability, and unique properties. This review article provides a comprehensive examination of the diverse applications of PVA and chitosan in three pivotal areas: tissue engineering, drug delivery, and biosensors. In tissue engineering, the discussion centres on how PVA and chitosan are engineered into scaffolds that not only support cell growth and differentiation but also promote tissue regeneration by closely mimicking the extracellular matrix. These scaffolds offer the necessary mechanical strength and adaptability for various biomedical applications. For drug delivery, the article delves into the development of sophisticated controlled release systems and targeted drug carriers, highlighting the polymers' customizable properties and their mucoadhesive nature, which make them highly effective across multiple drug delivery methods. Furthermore, the potential of PVA and chitosan in biosensor technology is explored, particularly their ability to interact with biomolecules and their intrinsic conductivity attributes that are essential for creating sensitive, reliable, and biocompatible sensors for medical diagnostics. By synthesizing recent research findings and suggesting future research directions, this review underscores the versatility and critical role of PVA and chitosan in pushing the boundaries of biomedical innovation. It offers valuable insights for researchers and scientists dedicated to advancing healthcare through the application of these natural polymers.

Biomedical research grant resubmission: rates and factors related to success – a scoping review

ObjectivesMost first-time biomedical research grant applications are not funded. In the challenging research funding climate, resubmitting a grant application is a necessary task for scientists. Identifying which factors influence their...