Polycaprolactone/gelatin electrospun nanofibres containing biologically produced tellurium nanoparticles as a potential wound dressing scaffold: Physicochemical, mechanical, and biological characterisation

Design of Collagen and Gelatin-based Electrospun Fibers for Biomedical Purposes: An Overview

Collagen and gelatin are essential natural biopolymers commonly utilized in biomaterials and tissue engineering because of their excellent physicochemical and biocompatibility properties. They can be used either in combination with other biomacromolecules or particles or even exclusively for the enhancement of bone regeneration or for the development of biomimetic scaffolds. Collagen or gelatin derivatives can be transformed into nanofibrous materials with porous micro- or nanostructures and superior mechanical properties and biocompatibility using electrospinning technology. Specific attention was recently paid to electrospun mats of such biopolymers, due to their high ratio of surface area to volume, as well as their biocompatibility, biodegradability, and low immunogenicity. The fiber mats with submicro- and nanometer scale can replicate the extracellular matrix structure of human tissues and organs, making them highly suitable for use in tissue engineering due to their exceptional bioaffinity. The drawbacks may include rapid degradation and complete dissolution in aqueous media. The use of gelatin/collagen electrospun nanofibers in this form is thus greatly restricted for biomedicine. Therefore, the cross-linking of these fibers is necessary for controlling their aqueous solubility. This led to enhanced biological characteristics of the fibers, rendering them excellent options for various biomedical uses. The objective of this review is to highlight the key research related to the electrospinning of collagen and gelatin, as well as their applications in the biomedical field. The review features a detailed examination of the electrospinning fiber mats, showcasing their varying structures and performances resulting from diverse solvents, electrospinning processes, and cross-linking methods. Judiciously selected examples from literature will be presented to demonstrate major advantages of such biofibers. The current developments and difficulties in this area of research are also being addressed.

Fundamental characteristics of ultrasonic green formulations using Avena sativa L. extract-mediated gold nanoparticles and electroconductive nanofibers for cardiovascular nursing care

In the pursuit of novel approaches to address chronic heart failure and enhance cardiovascular nursing care, environmentally sustainable nanomaterials have taken center stage. Recent progress in regenerative medicine has opened doors for the use of biocompatible biomaterials that provide mechanical support to damaged heart tissue and facilitate electrical signaling. This study was dedicated to developing advanced electroconductive nanofibers by incorporating eco-friendly Avena sativa L. extract-mediated gold nanoparticles (AuNPs) into polyaniline to create an intricate cardiac patch. The AuNPs were synthesized through an environmentally friendly chemical process aided by ultrasonic conditions. Comprehensive physicochemical analyses, such as UV-Vis spectroscopy, SEM, TEM, DPPH assay, and XRD, were carried out to characterize the AuNPs. These AuNPs were then blended with a polycaprolactone/gelatin polymeric solution and electrospun to fabricate cardiac patches, which underwent thorough evaluation using various techniques. The resulting cardiac patch demonstrated excellent hemocompatibility, antioxidant properties, and cytocompatibility, offering a promising therapeutic approach for myocardial infarctions and the advancement of cardiovascular nursing care.

In situ, synthesis of chitosan fabricated tellurium nanoparticles for improved antimicrobial and anticancer applications

The emergence of antibiotic resistance has had a severe impact on human health and economic burdens, drawing attention to the development of novel antimicrobial therapies. Polymer-metal composites have shown evidence of therapeutic applications by exerting antimicrobial effects and delivering these antimicrobials with biocompatibility. Therefore, this study prepared and characterized chitosan (CS)-fabricated tellurium nanoparticles (Te NPs) for enhanced antimicrobial, antioxidant, and cytotoxicity applications. The CS-Te NPs were spherical, polydisperse, and distributed within the CS matrix with an average size of 37.48 ± 14.56 nm, as confirmed by TEM analysis. CS-Te NPs exhibited positive zeta potential in neutral (pH 7.0: 7.90 ± 1.86 mV) and acidic environment. XRD analysis confirmed the crystalline nature of CS-Te NPs, and these nanoparticles exhibited good thermal and less porosity. A higher release of Te ions occurred from CS-Te NPs at an acidic pH. Further, CS-Te NPs displayed stronger antibacterial and antibiofilm activity against E. coli and S. enterica. Furthermore, CS-Te NPs exhibited significant free radical scavenging activity against ABTS and DPPH free radicals. Moreover, these nanoparticles demonstrated cytotoxicity against cancerous cells (A549 and PC3 cells) when compared to normal cells (NIH3T3 cells). Therefore, this study suggests that CS-Te NPs could serve as a substantial therapeutic agent.

Development of Ag NPs/allantoin loaded PCL/GEL electrospun nanofibers for topical wound treatment

In the present study, the allantoin and silver nanoparticle (Ag NPs) loaded poly caprolactone/gelatin (PCL/GEL) nanofibers produced using electrospinning technique and their cyto-compatibility and wound healing activity were evaluated in vitro and in vivo. The SEM imaging revealed diameters of 278.8 ± 10 and 240.6 ± 12 nm for PCL/GEL/Ag NPs and PCL/GEL/Ag NPs/allantoin scaffolds. The Ag NPs entrapment into scaffolds was evaluated by FTIR analysis and EDX mapping. Both scaffolds containing Ag NPs and Ag NPs/allantoin exhibited valuable wound healing activity in Wistar rat animal model. The profound granulation tissue formation, high collagen deposition in coordination with low level of edema and inflammatory cells in Ag NPs/allantoin loaded scaffolds resulted in complete and mature re-epithelialization in giving the healing score (12 out of 12) equal to positive control group to the wounds treated with these scaffolds. It was concluded that the Ag NPs/allantoin loaded scaffolds regarding to their good antibacterial activity and excellent wound healing activity could be introduced as new effective wound dressing materials.

Novel Capturer-Catalyst Microreactor System with a Polypyrrole/Metal Nanoparticle Composite Incorporated in the Porous Honeycomb-Patterned Film

A composite of polypyrrole/metal nanoparticles (PPy/MNPs) was selectively incorporated into the pores of a honeycomb-patterned porous polycaprolactone polymer film to fabricate a novel capturer-catalyst microreactor system. This fabrication involved a modified breath figure method, where the polymer solution containing metal ions as an oxidizing agent was cast under humid conditions along with the pyrrole monomer through an interfacial reaction in a one-step in situ process. The higher hydrophilicity of the metal ions compared to the polymer solution led to their self-assembly around the pore surface, resulting in the selective incorporation of the PPy/MNP composite into the porous film. Copper (Cu), silver (Ag), and gold (Au) were used for the PPy/MNP fabrication. Various methods characterized the fabricated film. Strong catalytic degradations of methylene blue and methyl orange were obtained with PCL-PPy/MNPs. Recycling experiments showed no loss of activity even after five cycles of recycling. Comparative analysis of PCL-PPy, PCL-MNP, and PCL-PPy/MNP results indicated the synergistic action of PPy and MNPs in dye degradation. High-performance liquid chromatography and mass spectroscopy analyses confirmed dye degradation after treatment with a fabricated microreactor. PPy might have acted as a capturer of the dye molecule and MNPs as a catalyst, thereby enhancing the efficiency of dye degradation. Additionally, the PCL-PPy/Cu composite exhibited strong antimicrobial properties against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) with no cytotoxicity as measured by the MTT assay. Therefore, the fabricated microreactor film has promising applications in various fields.

Evolving Trends in Nanofibers for Topical Delivery of Therapeutics in Skin Disorders

Nanotechnology has yielded nanostructure-based drug delivery approaches, among which nanofibers have been explored and researched for the potential topical delivery of therapeutics. Nanofibers are filaments or thread-like structures in the nanometer size range that are fabricated using various polymers, such as natural or synthetic polymers or their combination. The size or diameter of the nanofibers depends upon the polymers, the techniques of preparation, and the design specification. The four major processing techniques, phase separation, self-assembly, template synthesis, and electrospinning, are most commonly used for the fabrication of nanofibers. Nanofibers have a unique structure that needs a multimethod approach to study their morphology and characterization parameters. They are gaining attention as drug delivery carriers, and the substantially vast surface area of the skin makes it a potentially promising strategy for topical drug products for various skin disorders such as psoriasis, skin cancers, skin wounds, bacterial and fungal infections, etc. However, the large-scale production of nanofibers with desired properties remains challenging, as the widely used electrospinning processes have certain limitations, such as poor yield, use of high voltage, and difficulty in achieving in situ nanofiber deposition on various substrates. This review highlights the insights into fabrication strategies, applications, recent clinical trials, and patents of nanofibers for different skin disorders in detail. Additionally, it discusses case studies of its effective utilization in the treatment of various skin disorders for a better understanding for readers.

PCL/Gelatin/Graphene Oxide Electrospun Nanofibers: Effect of Surface Functionalization on In Vitro and Antibacterial Response

The emergence of resistance to pathogenic bacteria has resulted from the misuse of antibiotics used in wound treatment. Therefore, nanomaterial-based agents can be used to overcome these limitations. In this study, polycaprolactone (PCL)/gelatin/graphene oxide electrospun nanofibers (PGO) are functionalized via plasma treatment with the monomeric groups diallylamine (PGO-M1), acrylic acid (PGO-M2), and tert-butyl acrylate (PGO-M3) to enhance the action against bacteria cells. The surface functionalization influences the morphology, surface wettability, mechanical properties, and thermal stability of PGO nanofibers. PGO-M1 and PGO-M2 exhibit good antibacterial activity against Staphylococcus aureus and Escherichia coli, whereas PGO-M3 tends to reduce their antibacterial properties compared to PGO nanofibers. The highest proportion of dead bacteria cells is found on the surface of hydrophilic PGO-M1, whereas live cells are colonized on the surface of hydrophobic PGO-M3. Likewise, PGO-M1 shows a good interaction with L929, which is confirmed by the high levels of adhesion and proliferation with respect to the control. All the results confirm that surface functionalization can be strategically used as a tool to engineer PGO nanofibers with controlled antibacterial properties for the fabrication of highly versatile devices suitable for different applications (e.g., health, environmental pollution).

State-of-the-Art Review of Electrospun Gelatin-Based Nanofiber Dressings for Wound Healing Applications

Electrospun nanofiber materials have been considered as advanced dressing candidates in the perspective of wound healing and skin regeneration, originated from their high porosity and permeability to air and moisture, effective barrier performance of external pathogens, and fantastic extracellular matrix (ECM) fibril mimicking property. Gelatin is one of the most important natural biomaterials for the design and construction of electrospun nanofiber-based dressings, due to its excellent biocompatibility and biodegradability, and great exudate-absorbing capacity. Various crosslinking approaches including physical, chemical, and biological methods have been introduced to improve the mechanical stability of electrospun gelatin-based nanofiber mats. Some innovative electrospinning strategies, including blend electrospinning, emulsion electrospinning, and coaxial electrospinning, have been explored to improve the mechanical, physicochemical, and biological properties of gelatin-based nanofiber mats. Moreover, numerous bioactive components and therapeutic agents have been utilized to impart the electrospun gelatin-based nanofiber dressing materials with multiple functions, such as antimicrobial, anti-inflammation, antioxidation, hemostatic, and vascularization, as well as other healing-promoting capacities. Noticeably, electrospun gelatin-based nanofiber mats integrated with specific functions have been fabricated to treat some hard-healing wound types containing burn and diabetic wounds. This work provides a detailed review of electrospun gelatin-based nanofiber dressing materials without or with therapeutic agents for wound healing and skin regeneration applications.