Electrospun polyvinyl-alcohol/gum arabic nanofibers: Biomimetic platform for in vitro cell growth and cancer nanomedicine delivery

Quercetin nanoparticles decorated on Arabic gum and polyvinyl alcohol composite as a film sensor for fluorescence detection of meropenem

Moving towards green chemistry to minimize the diverse effect of chemicals on human health and environment has become a great issue in chemistry. On the other hand, determination of pharmaceuticals is an important issue for both human health and environment. In this regard two natural and benign compounds such as quercetin a polyphenolic flavonoid and Arabic Gum (AG) a polysaccharide were used to construct a sensor for meropenem. Herein, a new method was established for the synthesis of AG and polyvinyl alcohol (PVA) composite decorated by quercetin nanoparticles (QUENPs) as a fluorimetric film sensor to measure meropenem. In order to embed QUENPs in the polymer composite substrate, first QUENPs were synthesized and then added to the prepared composite solution under optimal conditions. The characteristics of AG and PVA composite (AG-PVA) and AG-PVA composite decorated by QUENPs films (QUENPs-AG-PVA), before and after the addition of meropenem was studied by TEM, FT-IR and EDX-Mapping. The developed film sensor was placed in a holder made with 3D printer. The difference in the fluorescence intensity of the fabricated film before and after the addition of meropenem was taken as the signal for measuring meropenem. The effect of different parameters on the fabrication of film fluorimetric sensor such as the concentration of polymer solutions, the volume of QUENPs and the volume of glycerol were investigated. Factors affecting the measurement of meropenem such as pH, type of buffer, volume of meropenem solution added on the sensor and time were also investigated. Under the obtained optimum conditions, the calibration graph was linear in the concentration range of 50-800 ng mL-1 with a correlation coefficient (r) of 0.9976 and the detection limit was 42.6 ng mL-1. The relative standard deviation was 3.5% and 1.4%, for eight replicate determinations of 100 ng mL-1 and 400 ng mL-1 of meropenem, respectively. The proposed method was successfully utilized for determination of meropenem in blood serum, human urine and pharmaceutical samples.

Gums as Macromolecular Crowding Agents in Human Skin Fibroblast Cultures

Even though tissue-engineered medicines are under intense academic, clinical, and commercial investigation, only a handful of products have been commercialised, primarily due to the costs associated with their prolonged manufacturing. While macromolecular crowding has been shown to enhance and accelerate extracellular matrix deposition in eukaryotic cell culture, possibly offering a solution in this procrastinating tissue-engineered medicine development, there is still no widely accepted macromolecular crowding agent. With these in mind, we herein assessed the potential of gum Arabic, gum gellan, gum karaya, and gum xanthan as macromolecular crowding agents in WS1 skin fibroblast cultures (no macromolecular crowding and carrageenan were used as a control). Dynamic light scattering analysis revealed that all macromolecules had negative charge and were polydispersed. None of the macromolecules affected basic cellular function. At day 7 (the longest time point assessed), gel electrophoresis analysis revealed that all macromolecules significantly increased collagen type I deposition in comparison to the non-macromolecular crowding group. Also at day 7, immunofluorescence analysis revealed that carrageenan; the 50 µg/mL, 75 µg/mL, and 100 µg/mL gum gellan; and the 500 µg/mL and 1000 µg/mL gum xanthan significantly increased both collagen type I and collagen type III deposition and only carrageenan significantly increased collagen type V deposition, all in comparison to the non-macromolecular crowding group at the respective time point. This preliminary study demonstrates the potential of gums as macromolecular crowding agents, but more detailed biological studies are needed to fully exploit their potential in the development of tissue-engineered medicines.

Architecture of a dual biocompatible platform to immobilize genistin: fabrication with physio-chemical and in vitro evaluation

The design of biocompatible cell culture substrates and electrospun nanofibers can improve cell proliferation and behavior in laboratory conditions for tissue engineering applications in medicine. In this research, genistin was obtained by extracting from soybean meal powder, and then by adding polycaprolactone (PCL), genistin nanocapsules were prepared. For the first time, we used a lipophilic nanophase (encapsulated genistin) coated in a hydrophilic nanophase (gelatin /polyvinyl alcohol) as a dual nanosystem by the electrospinning method. In the approach, the nanofibers mimic the natural extracellular matrix, interact favorably with cells being cultured from one side, and raise the local concentration of a bioactive compound at the cell surface. The encapsulated drug which was inserted in fibers with a loading percentage of 92.01% showed appropriate and significant controlled release using high-performance liquid chromatography (HPLC). To prove the experiments, analysis using an ultraviolet-visible spectrometer (UV-Vis), 1H NMR spectrometer, Fourier transforms infrared spectrometer (FTIR), mechanical test, scanning electron microscope (SEM) and microscope transmission electron microscopy (TEM) was performed. The sample synthesized with 40% drug using the MTT method exhibited remarkable biological effects, viability, and non-toxicity. Additionally, significant proliferation and adhesion on the mouse fibroblast cell line L929 were observed within a 72-h timeframe.

Stimuli-responsive electrospun nanofibers for drug delivery, cancer therapy, wound dressing, and tissue engineering

The stimuli-responsive nanofibers prepared by electrospinning have become an ideal stimuli-responsive material due to their large specific surface area and porosity, which can respond extremely quickly to external environmental incitement. As an intelligent drug delivery platform, stimuli-responsive nanofibers can efficiently load drugs and then be stimulated by specific conditions (light, temperature, magnetic field, ultrasound, pH or ROS, etc.) to achieve slow, on-demand or targeted release, showing great potential in areas such as drug delivery, tumor therapy, wound dressing, and tissue engineering. Therefore, this paper reviews the recent trends of stimuli-responsive electrospun nanofibers as intelligent drug delivery platforms in the field of biomedicine.

Green Routes for Bio-Fabrication in Biomedical and Pharmaceutical Applications

In the last decade, significant advances in nanotechnologies, rising from increasing knowledge and refining of technical practices in green chemistry and bioengineering, enabled the design of innovative devices suitable for different biomedical applications. In particular, novel bio-sustainable methodologies are developing to fabricate drug delivery systems able to sagely mix properties of materials (i.e., biocompatibility, biodegradability) and bioactive molecules (i.e., bioavailability, selectivity, chemical stability), as a function of the current demands for the health market. The present work aims to provide an overview of recent developments in the bio-fabrication methods for designing innovative green platforms, emphasizing the relevant impact on current and future biomedical and pharmaceutical applications.

pH-sensing hybrid hydrogels for non-invasive metabolism monitoring in tumor spheroids

The constant increase in cancer incidence and mortality pushes biomedical research towards the development of in vitro 3D systems able to faithfully reproduce and effectively probe the tumor microenvironment. Cancer cells interact with this complex and dynamic architecture, leading to peculiar tumor-associated phenomena, such as acidic pH conditions, rigid extracellular matrix, altered vasculature, hypoxic condition. Acidification of extracellular pH, in particular, is a well-known feature of solid tumors, correlated to cancer initiation, progression, and resistance to therapies. Monitoring local pH variations, non-invasively, during cancer growth and in response to drug treatment becomes extremely important for understanding cancer mechanisms. Here, we describe a simple and reliable pH-sensing hybrid system, based on a thermoresponsive hydrogel embedding optical pH sensors, that we specifically apply for non-invasive and accurate metabolism monitoring in colorectal cancer (CRC) spheroids. First, the physico-chemical properties of the hybrid sensing platform, in terms of stability, rheological and mechanical properties, morphology and pH sensitivity, were fully characterized. Then, the proton gradient distribution in the spheroids proximity, in the presence or absence of drug treatment, was quantified over time by time lapse confocal light scanning microscopy and automated segmentation pipeline, highlighting the effects of the drug treatment in the extracellular pH. In particular, in the treated CRC spheroids the acidification of the microenvironment resulted faster and more pronounced over time. Moreover, a pH gradient distribution was detected in the untreated spheroids, with more acidic values in proximity of the spheroids, resembling the cell metabolic features observed in vivo in the tumor microenvironment. These findings promise to shed light on mechanisms of regulation of proton exchanges by cellular metabolism being essential for the study of solid tumors in 3D in vitro models and the development of personalized medicine approaches.

Gum Arabic-mediated liquid exfoliation of transition metal dichalcogenides as photothermic anti-breast cancer candidates

Transition metal dichalcogenides (TMDs) have gained considerable attention for a broad range of applications, including cancer therapy. Production of TMD nanosheets using liquid exfoliation provides an inexpensive and facile route to achieve high yields. In this study, we developed TMD nanosheets using gum arabic as an exfoliating and stabilizing agent. Different types of TMDs, including MoS₂, WS₂, MoSe₂, and WSe₂ nanosheets, were produced using gum arabic and were characterized physicochemically. The developed gum arabic TMD nanosheets exhibited a remarkable photothermal absorption capacity in the near-infrared (NIR) region (808 nm and 1 W⋅cm^-2). The drug doxorubicin was loaded on the gum arabic-MoSe₂ nanosheets (Dox-G-MoSe₂), and the anticancer activity was evaluated using MDA-MB-231 cells and a water-soluble tetrazolium salt (WST-1) assay, live and dead cell assays, and flow cytometry. Dox-G-MoSe₂ significantly inhibited MDA-MB-231 cancer cell proliferation under the illumination ofan NIR laser at 808 nm. These results indicate that Dox-G-MoSe₂ is a potentially valuable biomaterial for breast cancer therapy.

Evaluation of cashew gum-polyvinyl alcohol (CG-PVA) electrospun nanofiber mat for scarless wound healing in a murine model

Modern-day treatment for burns and wounds demands scarless healing which is becoming a challenging clinical problem. Thus, to alleviate such issues, it becomes essential to develop biocompatible and biodegradable wound dressing material for skin tissue regeneration, which could heal the wound in a very short span leaving no scars. The present study focuses on the development of nanofiber of Cashew gum polysaccharide-Polyvinyl alcohol using electrospinning. The prepared nanofiber was optimized based on uniformity of fiber diameter (FESEM), mechanical property (Tensile Strength), and optical contact angle (OCA) and was subjected to evaluation of: antimicrobial activity against Streptococcus aureus and Escherichia coli, hemocompatibility, and in-vitro biodegradability. The nanofiber was also characterized using different analytical techniques including thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray diffraction. The cytotoxicity was also investigated on L929 fibroblast cells using an SRB assay. The in-vivo wound healing assay showed accelerated healing in comparison to untreated wounds. The in-vivo wound healing assay and histopathological slides of regenerated tissue confirmed that the nanofiber has the potential to accelerate healing properties.

Preparation and Investigation of Thermally Annealed Zein-Propolis Electrospun Nanofibers for Biomedical Applications

Zein, a corn-derived protein, has a variety of applications ranging from drug delivery to tissue engineering and wound healing. This work aims to develop a biocompatible scaffold for dermal applications based on thermally annealed electrospun propolis-loaded zein nanofibers. Pristine fibers' biocompatibility is determined in vitro. Next, propolis from Melipona quadrifasciata is added to the fibers at different concentrations (5% to 25%), and the scaffolds are studied. The physicochemical properties of zein/propolis precursor dispersions are evaluated and the results are correlated to the fibers' properties. Due to zein's and propolis' very favorable interactions, which are responsible for the increase in the dispersions surface tension, nanometric size ribbon-like fibers ranging from 420 to 575 nm are obtained. The fiber's hydrophobicity is not dependent on propolis concentration and increases with the annealing procedure. Propolis inhibitory concentration (IC₅₀ ) is determined as 61.78 µg mL^-1 . When loaded into fibers, propolis is gradually delivered to cells as Balb/3T3 fibroblasts and are able to adhere, grow, and interact with pristine and propolis-loaded fibers, and cytotoxicity is not observed. Therefore, the zein-propolis nanofibers are considered biocompatible and safe. The results are promising and provide prospects for the development of wound-healing nanofiber patches-one of propolis' main applications.

Electrospun Nanofiber Composites for Drug Delivery: A Review on Current Progresses

A medication’s approximate release profile should be sustained in order to generate the desired therapeutic effect. The drug’s release site, duration, and rate must all be adjusted to the drug’s therapeutic aim. However, when designing drug delivery systems, this may be a considerable hurdle. Electrospinning is a promising method of creating a nanofibrous membrane since it enables drugs to be placed in the nanofiber composite and released over time. Nanofiber composites designed through electrospinning for drug release purposes are commonly constructed of simple structures. This nanofiber composite produces matrices with nanoscale fiber structure, large surface area to volume ratio, and a high porosity with small pore size. The nanofiber composite’s large surface area to volume ratio can aid with cell binding and multiplication, drug loading, and mass transfer processes. The nanofiber composite acts as a container for drugs that can be customized to a wide range of drug release kinetics. Drugs may be electrospun after being dissolved or dispersed in the polymer solution, or they can be physically or chemically bound to the nanofiber surface. The composition and internal structure of the nanofibers are crucial for medicine release patterns.

Drug Delivery Systems for Photodynamic Therapy: The Potentiality and Versatility of Electrospun Nanofibers

Recently, photodynamic therapy (PDT) has become a promising approach for the treatment of a broad range of diseases, including oncological and infectious diseases. This minimally invasive and localized therapy is based on the production of reactive oxygen species (ROS) able to destroy cancer cells and inactivate pathogens by combining the use of photosensitizers (PSs), light and molecular oxygen. To overcome the drawbacks of drug systemic administration, drug delivery systems (DDS) can be used to carrier the PSs, allowing higher therapeutic efficacy and minimal toxicological effects. Polymeric nanofibers produced by electrospinning emerged as powerful platforms for drug delivery applications. Electrospun nanofibers exhibit outstanding characteristics, such as large surface area to volume ratio associated with high drug loading, high porosity, flexibility, ability to incorporate and release a wide variety of therapeutic agents, biocompatibility and biodegradability. Due to the versatility of this technique, fibers with different morphologies and functionalities, including drug release profile can be produced. The possibility of scalability makes electrospinning even more attractive for the development of DDS. This review aims to explore and show an up to date of the huge potential of electrospun nanofibers as DDS for different PDT applications and discuss the opportunities and challenges in this field. This article is protected by copyright. All rights reserved.