Diclofenac Embedded in Silk Fibroin Fibers as a Drug Delivery System

Optimization of Diclofenac-Loaded Bicomponent Nanofibers: Effect of Gelatin on In Vitro and In Vivo Response

The use of electrospun fibers as anti-inflammatory drug carriers is currently one of the most interesting approaches for the design of drug delivery systems. In recent years, biodegradable polymers blended with naturally derived ones have been extensively studied to fabricate bioinspired platforms capable of driving biological responses by releasing selected molecular/pharmaceutical signals. Here, sodium diclofenac (DicNa)-loaded electrospun fibers, consisting of polycaprolactone (PCL) or gelatin-functionalized PCL, were studied to evaluate fibroblasts' in vitro and in vivo response. In vitro studies demonstrated that cell adhesion of L929 cells (≈70%) was not affected by the presence of DicNa after 4 h. Moreover, the initial burst release of the drug from PD and PGD fibers, e.g., 80 and 48%, respectively, after 5 h-combined with its sustained release-did not produce any cytotoxic effect and did not negatively influence the biological activity of the cells. In particular, it was demonstrated that the addition of gelatin concurred to slow down the release mechanism, thus limiting the antiproliferative effect of DicNa, as confirmed by the significant increase in cell viability and collagen deposition after 7 days, with respect to PCL alone. In vivo studies in a rat subcutaneous model also confirmed the ability of DicNa-loaded fibers to moderate the inflammatory/foreign body response independently through the presence of gelatin that played a significant role in supporting the formation of small-caliber vessels after 10 days of implantation. All of these results suggest using bicomponent fibers loaded with DicNa as a valid therapeutic tool capable of supporting the wound healing process and limiting in vivo inflammation and rejection phenomena.

Applications and Potentials of a Silk Fibroin Nanoparticle Delivery System in Animal Husbandry

Silk fibroin (SF), a unique natural polymeric fibrous protein extracted from Bombyx mori cocoons, accounts for approximately 75% of the total mass of silk. It has great application prospects due to its outstanding biocompatibility, biodegradability, low immunogenicity, and mechanical stability. Additionally, it is non-toxic and environmentally friendly. Nanoparticle delivery systems constructed with SF can improve the bioavailability of the carriers, increase the loading rates, control the release behavior of the deliverables, and enhance their action efficiencies. Animal husbandry is an integral part of agriculture and plays a vital role in the development of the rural economy. However, the pillar industry experiences a lot of difficulties, like drug abuse while treating major animal diseases, and serious environmental pollution, restricting sustainable development. Interestingly, the limited use cases of silk fibroin nanoparticle (SF NP) delivery systems in animal husbandry, such as veterinary vaccines and feed additives, have shown great promise. This paper first reviews the SF NP delivery system with regard to its advantages, disadvantages, and applications. Moreover, we describe the application status and developmental prospects of SF NP delivery systems to provide theoretical references for further development in livestock production and promote the high-quality and healthy development of animal husbandry.

Electrospun Nanofiber-Based Drug Carrier to Manage Inflammation

Significance: Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most widely prescribed drugs to treat inflammation and related ailments. In recent years, loading these drugs onto nanodevices like nanoparticles, nanofibers, etc. as a drug delivery system has gained momentum due to its desirable properties and advantages. The purpose of this review is to examine the existing research on the potential and novel use of nanofiber-assisted delivery of NSAIDs. Recent Advances: Electrospun nanofibers have recently garnered considerable attention from researchers in a variety of sectors. They have proved to be promising vehicles for drug delivery systems because of their exceptional and favorable features like prolonged drug release, controllable porosity, and high surface area. In this article, various polymers and even combinations of polymers loaded with single or multiple drugs were analyzed to achieve the desired drug release rates (burst, sustained, and biphasic) from the electrospun nanofibers. Critical Issues: The administration of these medications can induce major adverse effects, causing patients discomfort. Thus, encapsulating these drugs within electrospun nanofibers helps to reduce the severity of side effects while also providing additional benefits such as targeted and controlled drug release, reduced toxicity, and long-lasting effects of the drug with lower amounts of administration. Future Directions: This review covers previous research on the delivery of NSAIDs using electrospun nanofibers as the matrix. Also, this study intends to aid in the development of enhanced drug delivery systems for the treatment of inflammation and related issues.

Development of nanostructured formulation from naringenin and silk fibroin and application for inhibition of lipoxygenase (LOX)

A simple low-energy method was used to obtain polymeric nanoparticles containing silk fibroin (SF), fatty butyl esters (oily phase) and the flavonoid naringenin. Experimental planning (Box-Behnken) was applied to investigate the optimal conditions for three factors (variation of the concentrations of SF, naringenin and fatty butyl ester) at three levels, with evaluation of particle size, polydispersity index (PDI) and zeta potential (ZP) as responses. The results showed that the polymeric particle was formed with sizes of 179.6 to 633.9 nm, PDI of 0.33 to 0.77 and ZP of -60.4 to -38.8 mV. The best responses under the optimized conditions (Nari-SF 9 and 15) were characterized through transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), visible ultraviolet (UV-vis) and fluorescence, which confirmed that coated nanoparticles had been obtained. It was shown that the nanoformulation had excellent stability, the bioavailability of naringenin had been improved through use of the biopolymer and high inhibition of the enzyme lipoxygenase had been achieved in vitro.

Silk Fibroin Combined with Electrospinning as a Promising Strategy for Tissue Regeneration

The development of tissue engineering scaffolds is of great significance for the repair and regeneration of damaged tissues and organs. Silk fibroin (SF) is a natural protein polymer with good biocompatibility, biodegradability, excellent physical and mechanical properties and processability, making it an ideal universal tissue engineering scaffold material. Nanofibers prepared by electrospinning have attracted extensive attention in the field of tissue engineering due to their excellent mechanical properties, high specific surface area, and similar morphology as to extracellular matrix (ECM). The combination of silk fibroin and electrospinning is a promising strategy for the preparation of tissue engineering scaffolds. In this review, the research progress of electrospun silk fibroin nanofibers in the regeneration of skin, vascular, bone, neural, tendons, cardiac, periodontal, ocular and other tissues is discussed in detail.

Photoluminescent Gold/BSA Nanoclusters (AuNC@BSA) as Sensors for Red-Fluorescence Detection of Mycotoxins

The BSA-encapsulated gold nanoclusters (AuNC@BSA) have drawn considerable interest and demonstrated applications as biological sensors. In this study, we demonstrated that the red-emitting AuNC@BSA prepared using a modified procedure fully retained the binding of standard BSA-ligands (small molecule drugs), significantly improving fluorescence detection in some cases due to the red-emission property. Further, we showed that AuNC@BSA efficiently bind a series of aflatoxin-related mycotoxins as well as the aliphatic mycotoxin FB1, reporting interactions in the nanomolar range by instantaneous emission change at 680 nm. Such red emission detection is advantageous over current detection strategies for the same mycotoxins, based on complex mass spectrometry procedures or, eventually (upon chemical modification of the mycotoxin), by fluorescence detection in the UV range (<400 nm). The later technique yields fluorescence strongly overlapping with the intrinsic absorption and emission of biorelevant mixtures in which mycotoxins appear. Thus, here we present a new approach using the AuNC@BSA red fluorescence reporter for mycotoxins as a fast, cheap, and simple detection technique that offers significant advantages over currently available methods.

Applications of Novel Biodegradable Polymeric Materials

Commonly used traditional polymeric materials have many advantages, although their resistance to biological agents causes a negative impact on the environment [...].

Biomaterials and Extracellular Vesicle Delivery: Current Status, Applications and Challenges

In this review, we will discuss the current status of extracellular vesicle (EV) delivery via biopolymeric scaffolds for therapeutic applications and the challenges associated with the development of these functionalized scaffolds. EVs are cell-derived membranous structures and are involved in many physiological processes. Naïve and engineered EVs have much therapeutic potential, but proper delivery systems are required to prevent non-specific and off-target effects. Targeted and site-specific delivery using polymeric scaffolds can address these limitations. EV delivery with scaffolds has shown improvements in tissue remodeling, wound healing, bone healing, immunomodulation, and vascular performance. Thus, EV delivery via biopolymeric scaffolds is becoming an increasingly popular approach to tissue engineering. Although there are many types of natural and synthetic biopolymers, the overarching goal for many tissue engineers is to utilize biopolymers to restore defects and function as well as support host regeneration. Functionalizing biopolymers by incorporating EVs works toward this goal. Throughout this review, we will characterize extracellular vesicles, examine various biopolymers as a vehicle for EV delivery for therapeutic purposes, potential mechanisms by which EVs exert their effects, EV delivery for tissue repair and immunomodulation, and the challenges associated with the use of EVs in scaffolds.

Electrospun SF/PLGA/ICG Composite Nanofibrous Membranes for Potential Wound Healing and Tumor Therapy

Indocyanine green (ICG) is a near-infrared (NIR) organic reagent for clinical bioimaging and phototherapy. It is a suitable photosensitizer for photodynamic antimicrobial chemotherapy (PACT). In this study, various ICG-loaded nanofibrous membranes were prepared. The water vapor transmission rate (WVTR) of SF/PLGA/20ICG was 3040.49 ± 157.11 g·m−2 day−1, which allowed the maintenance of a humid environment above the wound. The growth inhibition rates for S. aureus and E. coli were 91.53% and 87.95%, respectively. The nanofibrous membranes exhibited excellent antimicrobial performance. Cellular experiments showed that the nanofibrous membranes have good cytocompatibility and antitumor efficacy. SF/PLGA/20ICG showed good potential for application in wound healing and cancer therapy.

Electrospun Poly(ethylene Terephthalate)/Silk Fibroin Composite for Filtration Application

In this study, fibrous membranes from recycled-poly(ethylene terephthalate)/silk fibroin (r-PSF) were prepared by electrospinning for filtration applications. The effect of silk fibroin on morphology, fibers diameters, pores size, wettability, chemical structure, thermo-mechanical properties, filtration efficiency, filtration performance, and comfort properties such as air and water vapor permeability was investigated. The filtration efficiency (FE) and quality factor (Qf), which represents filtration performance, were calculated from penetration through the membranes using aerosol particles ranging from 120 nm to 2.46 μm. The fiber diameter influenced both FE and Qf. However, the basis weight of the membranes has an effect, especially on the FE. The prepared membranes were classified according to EN149, and the most effective was assigned to the class FFP1 and according to EN1822 to the class H13. The impact of silk fibroin on the air permeability was assessed. Furthermore, the antibacterial activity against bacteria S. aureus and E. coli and biocompatibility were evaluated. It is discussed that antibacterial activity depends not only on the type of used materials but also on fibrous membranes' surface wettability. In vitro biocompatibility of the selected samples was studied, and it was proven to be of the non-cytotoxic effect of the keratinocytes (HaCaT) after 48 h of incubation.

Application of an ultrasound semi-quantitative assessment in the degradation of silk fibroin scaffolds in vivo

BACKGROUND

Research on the degradation of silk fibroin (SF) scaffolds in vivo lacks uniform and effective standards and experimental evaluation methods. This study aims to evaluate the application of ultrasound in assessing the degradation of SF scaffolds.

METHODS

Two groups of three-dimensional regenerated SF scaffolds (3D RSFs) were implanted subcutaneously into the backs of Sprague-Dawley rats. B-mode ultrasound and hematoxylin and eosin (HE) staining were performed on days 3, 7, 14, 28, 56, 84, 112, 140, and 196. The cross-sectional areas for two groups of 3D RSFs that were obtained using these methods were semi-quantitatively analyzed and compared to evaluate the biodegradation of the implanted RSFs.

RESULTS

The 3D RSFs in the SF-A group were wholly degraded at the 28th week after implantation. In contrast, the 3D RSFs in the SF-B group were completely degraded at the 16th week. Ultrasonic examination showed that the echoes of 3D RSFs in both groups gradually decreased with the increase of the implantation time. In the early stages of degradation, the echoes of the samples were higher than the echo of the muscle. In the middle of degeneration, the echoes were equal to the echo of the muscle. In the later stage, the echoes of the samples were lower than that of the muscle. The above changes in the SF-B group were earlier than those in the SF-A group. Semi-quantitative analysis of the cross-sectional areas detected using B-mode ultrasound revealed that the degradations of the two 3D RSF groups were significantly different. The degradation rate of the SF-B group was found to be higher than that of the SF-A group. This was consistent with the semi-quantitative detection results for HE staining. Regression analysis showed that the results of the B-mode ultrasound and HE staining were correlated in both groups, indicating that B-mode ultrasound is a reliable method to evaluate the SF scaffold degradation in vivo.

CONCLUSIONS

This study suggests that B-mode ultrasound can clearly display the implanted SF scaffolds non-invasively and monitor the degradation of the different SF scaffolds after implantation in living organisms in real-time.

The Drug-Loaded Electrospun Poly(ε-Caprolactone) Mats for Therapeutic Application

Diclofenac sodium salt (DSS)-loaded electrospun nanofiber mats on the base of poly(ε-caprolactone) (PCL) were investigated as biocompatible nanofibrous mats for medical applications with the ability to inhibit bacterial infections. The paper presents the characteristics of fibrous mats made by electrospinning and determines the effect of medicament on the fiber morphology, chemical, mechanical and thermal properties, as well as wettability. PCL and DSS-loaded PCL nanofibrous mats were characterized using scanning electron microscopy, transmission electron microscopy, attenuated total reflectance-Fourier transform infrared spectrometry, dynamic mechanical analysis, and contact angle measurements. Electron paramagnetic resonance measurements confirmed the lifetime of DSS before and after application of high voltage during the electrospinning process. In vitro biocompatibility was studied, and it was proved to be of good viability with ~92% of the diploid human cells culture line composed of lung fibroblast (MRC 5) after 48 h of incubation. Moreover, the significant activity of DSS-loaded nanofibers against cancer cells, Ca Ski and HeLa, was established as well. It was shown that 12.5% (m/V) is the minimal concentration for antibacterial activity when more than 99% of Escherichia coli (Gram-negative) and 99% of Staphylococcus aureus (Gram-positive) have been exterminated.