Liver Extracellular Matrix-Based Nanofiber Scaffolds for the Culture of Primary Hepatocytes and Drug Screening.

Immortalized liver cell lines and primary hepatocytes are currently used as in vitro models for hepatotoxic drug screening. However, a decline in the viability and functionality of hepatocytes with time is an important limitation of these culture models. Advancements in tissue engineering techniques have allowed us to overcome this challenge by designing suitable scaffolds for maintaining viable and functional primary hepatocytes for a longer period of time in culture. In the current study, we fabricated liver-specific nanofiber scaffolds with polylactic acid (PLA) along with a decellularized liver extracellular matrix (LEM) by the electrospinning technique. The fabricated hybrid PLA-LEM scaffolds were more hydrophilic and had better swelling properties than the PLA scaffolds. The hybrid scaffolds had a pore size of 38 ± 8 µm and supported primary rat hepatocyte cultures for 10 days. Increased viability (2-fold increase in the number of live cells) and functionality (5-fold increase in albumin secretion) were observed in primary hepatocytes cultured on the PLA-LEM scaffolds as compared to those on conventional collagen-coated plates on day 10 of culture. A significant increase in CYP1A2 enzyme activity was observed in hepatocytes cultured on PLA-LEM hybrid scaffolds in comparison to those on collagen upon induction with phenobarbital. Drugs like acetaminophen and rifampicin showed the highest toxicity in hepatocytes cultured on hybrid scaffolds. Also, the lethal dose of these drugs in rodents was accurately predicted as 1.6 g/kg and 594 mg/kg, respectively, from the corresponding IC50 values obtained from drug-treated hepatocytes on hybrid scaffolds. Thus, the fabricated liver-specific electrospun scaffolds maintained primary hepatocyte viability and functionality for an extended period in culture and served as an effective ex vivo drug screening platform to predict an accurate in vivo drug-induced hepatotoxicity.

Evolution of Electrospinning in Liver Tissue Engineering.

The major goal of liver tissue engineering is to reproduce the phenotype and functions of liver cells, especially primary hepatocytes ex vivo. Several strategies have been explored in the recent past for culturing the liver cells in the most apt environment using biological scaffolds supporting hepatocyte growth and differentiation. Nanofibrous scaffolds have been widely used in the field of tissue engineering for their increased surface-to-volume ratio and increased porosity, and their close resemblance with the native tissue extracellular matrix (ECM) environment. Electrospinning is one of the most preferred techniques to produce nanofiber scaffolds. In the current review, we have discussed the various technical aspects of electrospinning that have been employed for scaffold development for different types of liver cells. We have highlighted the use of synthetic and natural electrospun polymers along with liver ECM in the fabrication of these scaffolds. We have also described novel strategies that include modifications, such as galactosylation, matrix protein incorporation, etc., in the electrospun scaffolds that have evolved to support the long-term growth and viability of the primary hepatocytes.

Curcumin loaded waste biomass resourced cellulosic nanofiber cloth as a potential scaffold for regenerative medicine: An in-vitro assessment.

This article demonstrates the development of nanofibrous cloths by electrospinning of renewable materials, i.e., curcumin-loaded 90% cellulose acetate (CA)/10% poly(ε-caprolactone) (PCL), for applications in regenerative medicine. The CA is derived from the biomass waste of the oil palm plantation (empty fruit bunch). The nanofiber scaffolds are characterized for the fiber morphology, microstructure, thermal properties, and wettability. The optimized smooth and bead-free electrospun fiber cloth contains 90% CA and 10% PCL in two curcumin compositions (0.5 and 1 wt%). The role of curcumin is shown to be two-fold: the first is its function as a drug and the second is its role in lowering the water contact angle and increasing the hydrophilicity. The hydrophilicity enhancements are related to the hydrogen bonding between the components. The enhanced hydrophilicity contributed to improve the swelling behavior of the scaffolds; the CA/PCL/Cur (0.5%) and the CA/PCL/Cur (1.0%) showed swelling of ~700 and 950%, respectively, in phosphate-buffered saline (PBS). The drug-release studies revealed the highest cumulative drug release of 60% and 78% for CA/PCL/Cur (0.5%) and CA/PCL/Cur (1.0%) nanofibers, respectively. The in-vitro studies showed that CA/PCL/Cur (0.5 wt%) and CA/PCL/Cur (1.0 wt%) nanofiber scaffolds facilitate a higher proliferation and expression of actin in fibroblasts than those scaffolds without curcumin for wound healing applications.

PEGylated Lipid Polymeric Nanoparticle-Encapsulated Acyclovir for In Vitro Controlled Release and Ex Vivo Gut Sac Permeation.

Currently, pharmaceutical research is directed wide range for developing new drugs for oral administration to target disease. Acyclovir formulation is having common issues of short half-life and poor permeability, causing messy treatment which results in patient incompliance. The present study formulates a lipid polymeric hybrid nanoparticles for antiviral acyclovir (ACV) agent with Phospholipon® 90G (lecithin), chitosan, and polyethylene glycol (PEG) to improve controlled release of the drugs. The study focused on the encapsulation of the ACV in lipid polymeric particle and their sustained delivery. The formulation developed for the self-assembly of chitosan and lecithin to form a shell encapsulating acyclovir, followed by PEGylation. Optimisation was performed via Box-Behnken Design (BBD), forming nanoparticles with size of 187.7 ± 3.75 nm, 83.81 ± 1.93% drug-entrapped efficiency (EE), and + 37.7 ± 1.16 mV zeta potential. Scanning electron microscopy and transmission electron microscopy images displayed spherical nanoparticles formation. Encapsulation of ACV and complexity with other physical parameters are confirmed through analysis using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. Nanoparticle produced was capable of achieving 24-h sustained release in vitro on gastric and intestinal environments. Ex vivo study proved the improvement of acyclovir's apparent permeability from 2 × 10-6 to 6.46 × 10-6 cm s-1. Acyclovir new formulation was achieved to be stable up to 60 days for controlled release of the drugs. Graphical abstract.

Biocompatible Aloe vera and Tetracycline Hydrochloride Loaded Hybrid Nanofibrous Scaffolds for Skin Tissue Engineering.

Aloe vera (AV) and tetracycline hydrochloride (TCH) exhibit significant properties such as anti-inflammatory, antioxidant and anti-bacterial activities to facilitate skin tissue engineering. The present study aims to develop poly-ε-caprolactone (PCL)/ AV containing curcumin (CUR), and TCH loaded hybrid nanofibrous scaffolds to validate the synergistic effect on the fibroblast proliferation and antimicrobial activity against Gram-positive and Gram-negative bacteria for wound healing. PCL/AV, PCL/CUR, PCL/AV/CUR and PCL/AV/TCH hybrid nanofibrous mats were fabricated using an electrospinning technique and were characterized for surface morphology, the successful incorporation of active compounds, hydrophilicity and the mechanical property of nanofibers. SEM revealed that there was a decrease in the fiber diameter (ranging from 360 to 770 nm) upon the addition of AV, CUR and TCH in PCL nanofibers, which were randomly oriented with bead free morphology. FTIR spectra of various electrospun samples confirmed the successful incorporation of AV, CUR and TCH into the PCL nanofibers. The fabricated nanofibrous scaffolds possessed mechanical properties within the range of human skin. The biocompatibility of electrospun nanofibrous scaffolds were evaluated on primary human dermal fibroblasts (hDF) by MTS assay, CMFDA, Sirius red and F-actin stainings. The results showed that the fabricated PCL/AV/CUR and PCL/AV/TCH nanofibrous scaffolds were non-toxic and had the potential for wound healing applications. The disc diffusion assay confirmed that the electrospun nanofibrous scaffolds possessed antibacterial activity and provided an effective wound dressing for skin tissue engineering.

Ramification of zinc oxide doped hydroxyapatite biocomposites for the mineralization of osteoblasts.

Far-flung evolution in tissue engineering enabled the development of bioactive and biodegradable materials to generate biocomposite nanofibrous scaffolds for bone repair and replacement therapies. Polymeric bioactive nanofibers are to biomimic the native extracellular matrix (ECM), delivering tremendous regenerative potentials for drug delivery and tissue engineering applications. It's been known from few decades that Zinc oxide (ZnO) nanoparticles are enhancing bone growth and providing proliferation of osteoblasts when incorporated with hydroxyapatite (HAp). We attempted to investigate the interaction between the human foetal osteoblasts (hFOB) with ZnO doped HAp incorporated biocomposite poly(L-lactic acid)-co-poly(ε-caprolactone) and silk fibroin (PLACL/SF) nanofibrous scaffolds for osteoblasts mineralization in bone tissue regeneration. The present study, we doped ZnO with HAp (ZnO(HAp) using the sol-gel ethanol condensation technique. The properties of PLACL/SF/ZnO(HAp) biocomposite nanofibrous scaffolds enhanced with doped and blended ZnO/HAp were characterized using Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Contact angle and Tensile studies to determine the morphology, functionality, wettability and stability. The in vitro study results showed that the addition of ZnO and HAp enhances the secretion of bone mineral matrix (98%) with smaller fiber diameter (139.4 ±â€¯27 nm) due to the presence of silk fibroin showing potential tensile properties (322.4%), and increased the proliferation of osteoblasts for bone tissue regeneration.

Fabrication of a biomimetic ZeinPDA nanofibrous scaffold impregnated with BMP-2 peptide conjugated TiO2 nanoparticle for bone tissue engineering.

A biomimetic Zein polydopamine based nanofiber scaffold was fabricated to deliver bone morphogenic protein-2 (BMP-2) peptide conjugated titanium dioxide nanoparticles in a sustained manner for investigating its osteogenic differentiation potential. To prolong its retention time at the target site, BMP-2 peptide has been conjugated to titanium dioxide nanoparticles owing to its high surface to volume ratio. The effect of biochemical cues from BMP-2 peptide and nanotopographical stimulation of electrospun Zein polydopamine nanofiber were examined for its enhanced osteogenic expression of human fetal osteoblast cells. The sustained delivery of bioactive signals, improved cell adhesion, mineralization, and differentiation could be attributed to its highly interconnected nanofibrous matrix with unique material composition. Further, the expression of osteogenic markers revealed that the fabricated nanofibrous scaffold possess better cell-biomaterial interactions. These promising results demonstrate the potential of the composite nanofibrous scaffold as an effective biomaterial substrate for bone regeneration.

Antibacterial glass-ionomer cement restorative materials: A critical review on the current status of extended release formulations.

Glass-ionomer cements (GICs) have been widely used for over forty years, because of their desirable properties in dentistry. The most important advantages of the GICs are associated with their ability to release long-term antimicrobial agents. However, GICs used as restorative materials have still lots of challenges due to their secondary caries and low mechanical properties. Recent studies showed that the fluoride-releasing activity of conventional GICs is inadequate for effectual antibacterial conservation in many cases. Therefore, many efforts have been proposed to modify the antibacterial features of GICs in order to prevent the secondary caries. Particularly, for achieving this goal GICs were incorporated into various biomaterials possessing antibacterial activities. The scope of this review is to assess systematically the extant researches addressing the antibacterial modifications in GICs in order to provide with an authoritative, at the same time in-depth understanding of controlled antibacterial release in this class of biomaterials. It also gives a whole perspective on the future developments of GICs and challenges related to antibacterial GICs.

Nanotechnology for the treatment of melanoma skin cancer.

Melanoma is the most aggressive type of skin cancer and has very high rates of mortality. An early stage melanoma can be surgically removed, with a survival rate of 99%. This literature review intends to elucidate the possibilities to treat melanoma skin cancer using hybrid nanofibers developed by advanced electrospinning process. In this review we have shown that the enhanced permeability and retention is the basis for using nanotechnology, aiming topical drug delivery. The importance of the detection of skin cancer in the early stages is directly related to non-metastatic effects and survival rates of melanoma cells. Inhibitors of protein kinase are already available in the market for melanoma treatment and are approved by the FDA; these agents are cobimetinib, dabrafenib, ipilimumab, nivolumab, trametinib, and vemurafenib. We also report a case study involving two different approaches for targeting melanoma skin cancer therapy, namely, magnetic-based core-shell particles and electrospun mats.

Hydroxyapatite-intertwined hybrid nanofibres for the mineralization of osteoblasts.

Advances in tissue engineering have enabled the development of bioactive composite materials to generate biomimetic nanofibrous scaffolds for bone replacement therapies. Polymeric biocomposite nanofibrous scaffolds architecturally mimic the native extracellular matrix (ECM), delivering tremendous regenerative potential for bone tissue engineering. In the present study, biocompatible poly(l-lactic acid)-co-poly(ε-caprolactone)-silk fibroin-hydroxyapatite-hyaluronic acid (PLACL-SF-HaP-HA) nanofibrous scaffolds were fabricated by electrospinning to mimic the native ECM. The developed nanofibrous scaffolds were characterized in terms of fibre morphology, functional group, hydrophilicity and mechanical strength, using SEM, FTIR, contact angle and tabletop tensile-tester, respectively. The nanofibrous scaffolds showed a higher level of pore size and increased porosity of up to 95% for the exchange of nutrients and metabolic wastes. The fibre diameters obtained were in the range of around 255 ± 13.4-789 ± 22.41 nm. Osteoblasts cultured on PLACL-SF-HaP-HA showed a significantly (p < 0.001) higher level of proliferation (53%) and increased osteogenic differentiation and mineralization (63%) for the inclusion of bioactive molecules SF-HA. Energy-dispersive X-ray analysis (EDX) data proved that the presence of calcium and phosphorous in PLACL-SF-HaP-HA nanofibrous scaffolds was greater than in the other nanofibrous scaffolds with cultured osteoblasts. The obtained results for functionalized PLACL-SF-HaP-HA nanofibrous scaffolds proved them to be a potential biocomposite for bone tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd.

3D Fabrication of Polymeric Scaffolds for Regenerative Therapy.

Recent advances in bioprinting technology have been used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. Organ printing and biofabrication provides great potential for the freeform fabrication of 3D living organs using cellular spheroids, biocomposite nanofibers, or bioinks as building blocks for regenerative therapy. Vascularization is often identified as a main technological barrier for building 3D organs in tissue engineering. 3D printing of living tissues starts with potential support of biomaterials to maintain structural integrity and degradation of certain time periods after printing of the scaffolds. Biofabrication is the production of complex living and nonliving biological products from raw materials such as cells, molecules, ECM, and biomaterials. Generally, two basic methods are used for the fabrication of scaffolds such as conventional/traditional fabrication processes and advance fabrication processes for engineering organs. A wide range of polymers and biomaterials are used for the fabrication of scaffolds in tissue engineering applications. 3D additive manufacturing is advancing day-by-day; however, there are various critical challenging factors used for fabricating 3D scaffolds. This review is aimed at understanding the various scaffold fabrication techniques, types of polymers and biomaterials used for the fabrication processes, various fields of applications, and different challenges faced in their fabrication of scaffolds in regenerative therapy.

Sequel of MgO nanoparticles in PLACL nanofibers for anti-cancer therapy in synergy with curcumin/ß-cyclodextrin.

Pharmaceutical industries spend more money in developing new and efficient methods for delivering successful drugs for anticancer therapy. Electrospun nanofibers and nanoparticles loaded with drugs have versatile biomedical applications ranging from wound healing to anticancer therapy. We aimed to attempt for fabricating elastomeric poly (l-lactic acid-co-ε-caprolactone) (PLACL) with Aloe Vera (AV), magnesium oxide (MgO) nanoparticles, curcumin (CUR) and ß-cyclodextrin (ß-CD) composite nanofibers to control the growth of MCF-7 cells for breast cancer therapy. The study focused on the interaction of MgO nanoparticle with CUR and ß-CD inhibiting the proliferation of Michigan Cancer Foundation-7 (MCF-7) breast cancer cells. FESEM micrographs of fabricated electrospun PLACL, PLACL/AV, PLACL/AV/MgO, PLACL/AV/MgO/CUR and PLACL/AV/MgO/ß-CD nanofibrous scaffolds achieved bead free, random and uniform nanofibers with fiber diameter in the range of 786±286, 507±171, 334±95, 360±94 and 326±80nm respectively. Proliferation of MCF-7 cells was decreased by 65.92% in PLACL/AV/MgO/CUR with respect to PLACL/AV/MgO nanofibrous scaffolds on day 9. The obtained results proved that 1% CUR interacting with MgO nanoparticles showed higher inhibition of MCF-7 cells among all other nanofibrous scaffolds thus serving as a promising biocomposite material system for the breast cancer therapy.

Latent Oxidative Polymerization of Catecholamines as Potential Cross-linkers for Biocompatible and Multifunctional Biopolymer Scaffolds.

Electrospinning of naturally occurring biopolymers for biological applications requires postspinning cross-linking for endurance in protease-rich microenvironments and prevention of rapid dissolution. The most commonly used cross-linkers often generate cytotoxic byproducts, which necessitate high concentrations or time-consuming procedures. Herein, we report the addition of "safe" catecholamine cross-linkers to collagen or gelatin dope solutions followed by electrospinning yielded junction-containing nanofibrous mats. Subsequent in situ oxidative polymerization of the catecholamines increased the density of soldered junctions and maintained the porous nanofiber architecture. This protocol imparted photoluminescence to the biopolymers, a smooth noncytotoxic coating, and good mechanical/structural stability in aqueous solutions. The utility of our approach was demonstrated by the preparation of durable antimicrobial wound dressings and mineralized osteoconductive scaffolds via peptide antibiotics and calcium chloride (CaCl2) incorporation into the dope solutions. The mineralized composite mats consist of amorphous calcium carbonate that enhanced the osteoblasts cell proliferation, differentiation, and expression of important osteogenic marker proteins. In proof-of-concept experiments, antibiotic-loaded mats displayed superior antimicrobial properties relative to silver (Ag)-based dressings, and accelerated wound healing in a porcine deep dermal burn injury model.

Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis.

Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering.

Bio-inspired in situ crosslinking and mineralization of electrospun collagen scaffolds for bone tissue engineering.

Bone disorders are the most common cause of severe long term pain and physical disability, and affect millions of people around the world. In the present study, we report bio-inspired preparation of bone-like composite structures by electrospinning of collagen containing catecholamines and Ca(2+). The presence of divalent cation induces simultaneous partial oxidative polymerization of catecholamines and crosslinking of collagen nanofibers, thus producing mats that are mechanically robust and confer photoluminescence properties. Subsequent mineralization of the mats by ammonium carbonate leads to complete oxidative polymerization of catecholamines and precipitation of amorphous CaCO3. The collagen composite scaffolds display outstanding mechanical properties with Young's modulus approaching the limits of cancellous bone. Biological studies demonstrate that human fetal osteoblasts seeded on to the composite scaffolds display enhanced cell adhesion, penetration, proliferation, differentiation and osteogenic expression of osteocalcin, osteopontin and bone matrix protein when compared to pristine collagen or tissue culture plates. Among the two catecholamines, mats containing norepinephrine displayed superior mechanical, photoluminescence and biological properties than mats loaded with dopamine. These smart multifunctional scaffolds could potentially be utilized to repair and regenerate bone defects and injuries.

Recent advancements in nanotechnological strategies in selection, design and delivery of biomolecules for skin regeneration.

Skin is a very complex organ and hence designing a bioengineered skin model replicating the essential physiological characteristics for replacing the diseased or damaged parts has been a challenging goal for many. Newer technologies for satisfying most of the criteria are being attempted with the copious efforts of biologists, engineers, physiologists, using multitude of features in combination. Amongst them nanotechnology based biomaterials have gained prominence owing to the enhanced pharmacokinetics, bio-distribution profile, extended half-life and reduced side effects. Designing a matrix that can be assimilated into the body during the regeneration and delivering the essential pharmacological agents in a temporal and spatially specific manner is a tremendous goal. This review essentially deals with the various approaches for designing a multidisciplinary translational smart matrix for addressing the various skin related ailments.

Biomimetic approaches for cell implantation to the restoration of infarcted myocardium.

Compelling evidences accumulated over the years have proven stem cells as a promising source for regenerative medicine. However, the inadequacy with the design of delivery modalities has prolonged the research in realizing an ideal cell-based approach for the regeneration of infarcted myocardium. Currently, some modest improvements in cardiac function have been documented in clinical trials with stem cell treatments, although regenerating a fully functional myocardium remains a dream for cardiac surgeons. This review provides an overview on the significance of stem cell therapy, the current attempts to resolve the drawbacks with the cell implantation approach and the various stratagems adopted with electrospun hybrid nanofibers for implementation in myocardial regenerative therapy.

Controlled release of drugs in electrosprayed nanoparticles for bone tissue engineering.

Generating porous topographic substrates, by mimicking the native extracellular matrix (ECM) to promote the regeneration of damaged bone tissues, is a challenging process. Generally, scaffolds developed for bone tissue regeneration support bone cell growth and induce bone-forming cells by natural proteins and growth factors. Limitations are often associated with these approaches such as improper scaffold stability, and insufficient cell adhesion, proliferation, differentiation, and mineralization with less growth factor expression. Therefore, the use of engineered nanoparticles has been rapidly increasing in bone tissue engineering (BTE) applications. The electrospray technique is advantageous over other conventional methods as it generates nanomaterials of particle sizes in the micro/nanoscale range. The size and charge of the particles are controlled by regulating the polymer solution flow rate and electric voltage. The unique properties of nanoparticles such as large surface area-to-volume ratio, small size, and higher reactivity make them promising candidates in the field of biomedical engineering. These nanomaterials are extensively used as therapeutic agents and for drug delivery, mimicking ECM, and restoring and improving the functions of damaged organs. The controlled and sustained release of encapsulated drugs, proteins, vaccines, growth factors, cells, and nucleotides from nanoparticles has been well developed in nanomedicine. This review provides an insight into the preparation of nanoparticles by electrospraying technique and illustrates the use of nanoparticles in drug delivery for promoting bone tissue regeneration.