Biocompatible Electrospun Polycaprolactone-Polyaniline Scaffold Treated with Atmospheric Plasma to Improve Hydrophilicity

Engineering an Extracellular Matrix Mimic Using Hemoglobin Protein Nanofibrils

Extracellular matrix (ECM) is essential for tissue development, providing structural support and a microenvironment that is necessary for cells. As tissue engineering advances, there is a growing demand for ECM mimics. Polycaprolactone (PCL) is a commonly used synthetic polymer for ECM mimic materials. However, its biologically inactive surface limits its direct application in tissue engineering. Our study aimed to improve the biocompatibility of PCL by incorporating hemoglobin nanofibrils (HbFs) into PCL using an electrospinning technique. HbFs were formed from bovine hemoglobin (Hb) extracted from industrial byproducts and designed to offer PCL an improved cell adhesion property. The fabricated HbFs@PCL electrospun scaffold exhibits improved fibroblast adherence, proliferation, and deeper fibroblast infiltration into the scaffold compared with the pure PCL scaffold, indicating its potential to be an ECM mimic. This study represents the pioneering utilization of Hb-sourced nanofibrils in the electrospun PCL scaffolds for tissue engineering applications.

Biomaterials for direct cardiac repair-A rapid scoping review 2012-2022

A plethora of biomaterials for heart repair are being tested worldwide for potential clinical application. These therapeutics aim to enhance the quality of life of patients with heart disease using various methods to improve cardiac function. Despite the myriad of therapeutics tested, only a minority of these studied biomaterials have entered clinical trials. This rapid scoping review aims to analyze literature available from 2012 to 2022 with a focus on clinical trials using biomaterials for direct cardiac repair, i.e., where the intended function of the biomaterial is to enhance the repair of the endocardium, myocardium, epicardium or pericardium. This review included neither biomaterials related to stents and valve repair nor biomaterials serving as vehicles for the delivery of drugs. Surprisingly, the literature search revealed that only 8 different biomaterials mentioned in 23 different studies out of 7038 documents (journal articles, conference abstracts or clinical trial entries) have been tested in clinical trials since 2012. All of these, intended to treat various forms of ischaemic heart disease (heart failure, myocardial infarction), were of natural origin and most used direct injections as their delivery method. This review thus reveals notable gaps between groups of biomaterials tested pre-clinically and clinically. STATEMENT OF SIGNIFICANCE: Rapid scoping review of clinical application of biomaterials for cardiac repair. 7038 documents screened; 23 studies mention 8 different biomaterials only. Biomaterials for repair of endocardium, myocardium, epicardium or pericardium. Only 8 different biomaterials entered clinical trials in the past 10 years. All of the clinically translated biomaterials were of natural origin.

Biofabrication of biomimetic undulating microtopography at the dermal-epidermal junction and its effects on the growth and differentiation of epidermal cells

The undulating microtopography located at the junction of the dermis and epidermis of the native skin is called rete ridges (RRs), which plays an important role in enhancing keratinocyte function, improving skin structure and stability, and providing three-dimensional (3D) microenvironment for skin cells. Despite some progress in recent years, most currently designed and manufactured tissue-engineered skin models still cannot replicate the RRs, resulting in a lack of biological signals in the manufactured skin models. In this study, a composite manufacturing method including electrospinning, 3D printing, and functional coating was developed to produce the epidermal models with RRs. Polycaprolactone (PCL) nanofibers were firstly electrospun to mimic the extracellular matrix environment and be responsible for cell attachment. PCL microfibers were then printed onto top of the PCL nanofibers layer by 3D printing to quickly prepare undulating microtopography and finally the entire structures were dip-coated with gelatin hydrogel to form a functional coating layer. The morphology, chemical composition, and structural properties of the fabricated models were studied. The results proved that the multi-process composite fabricated models were suitable for skin tissue engineering. Live and dead staining, cell counting kit-8 (CCK-8) as well as histology (haematoxylin and eosin (HE) methodology) and immunofluorescence (primary and secondary antibodies combination assay) were used to investigate the viability, metabolic activity, and differentiation of skin cells forin vitroculturing.In vitroresults showed that each model had high cell viability, good proliferation, and the expression of differentiation marker. It was worth noting that the sizes of the RRs affected the cell growth status of the epidermal models. In addition, the unique undulation characteristics of the epidermal-dermal junction can be reproduced in the developed epidermal models. Overall, thesein vitrohuman epidermal models can provide valuable reference for skin transplantation, screening and safety evaluation of drugs and cosmetics.

Cold atmospheric plasma modified polycaprolactone solution prior to electrospinning: A novel approach for improving quercetin-loaded nanofiber drug delivery systems

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.

Designing Electrical Stimulation Platforms for Neural Cell Cultivation Using Poly(aniline): Camphorsulfonic Acid

Electrical stimulation is a powerful strategy to improve the differentiation of neural stem cells into neurons. Such an approach can be implemented, in association with biomaterials and nanotechnology, for the development of new therapies for neurological diseases, including direct cell transplantation and the development of platforms for drug screening and disease progression evaluation. Poly(aniline):camphorsulfonic acid (PANI:CSA) is one of the most well-studied electroconductive polymers, capable of directing an externally applied electrical field to neural cells in culture. There are several examples in the literature on the development of PANI:CSA-based scaffolds and platforms for electrical stimulation, but no review has examined the fundamentals and physico-chemical determinants of PANI:CSA for the design of platforms for electrical stimulation. This review evaluates the current literature regarding the application of electrical stimulation to neural cells, specifically reviewing: (1) the fundamentals of bioelectricity and electrical stimulation; (2) the use of PANI:CSA-based systems for electrical stimulation of cell cultures; and (3) the development of scaffolds and setups to support the electrical stimulation of cells. Throughout this work, we critically evaluate the revised literature and provide a steppingstone for the clinical application of the electrical stimulation of cells using electroconductive PANI:CSA platforms/scaffolds.

In Vitro and In Vivo Evaluation of a Polycaprolactone (PCL)/Polylactic-Co-Glycolic Acid (PLGA) (80:20) Scaffold for Improved Treatment of Chondral (Cartilage) Injuries

Articular cartilage is a specialized tissue that provides a smooth surface for joint movement and load transmission. Unfortunately, it has limited regenerative capacity. Tissue engineering, combining different cell types, scaffolds, growth factors, and physical stimulation has become an alternative for repairing and regenerating articular cartilage. Dental Follicle Mesenchymal Stem Cells (DFMSCs) are attractive candidates for cartilage tissue engineering because of their ability to differentiate into chondrocytes, on the other hand, the polymers blend like Polycaprolactone (PCL) and Poly Lactic-co-Glycolic Acid (PLGA) have shown promise given their mechanical properties and biocompatibility. In this work, the physicochemical properties of polymer blends were evaluated by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) and were positive for both techniques. The DFMSCs demonstrated stemness by flow cytometry. The scaffold showed to be a non-toxic effect when we evaluated it with Alamar blue, and the samples were analyzed using SEM and phalloidin staining to evaluate cell adhesion to the scaffold. The synthesis of glycosaminoglycans was positive on the construct in vitro. Finally, the PCL/PLGA scaffold showed a better repair capacity than two commercial compounds, when tested in a chondral defect rat model. These results suggest that the PCL/PLGA (80:20) scaffold may be suitable for applications in the tissue engineering of articular hyaline cartilage.

Polyaniline-polycaprolactone electrospun nanofibrous mat: new polymeric support with anion exchange characteristic for immobilizing liquid membrane in efficient on-chip electromembrane extraction of polar acidic drugs

The potential of application of an electrospun nanofiber sheet as new polymeric support for immobilizing the liquid membrane, instead of a common commercial polypropylene sheet, in on-chip electromembrane extraction (EME) of some acidic polar drugs followed by HPLC with ultraviolet detection is presented. The nanofiber sheet was prepared by electrospinning a mixture of polycaprolactone and polyaniline. The successful synthesis of the electrospun nanofiber sheet was confirmed by field emission-scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, and atomic force microscopy. Several parameters affecting the efficiency of the microextraction method, including pHs of the donor and acceptor phases, applied voltage, sample flow rate, phosphate content of the acceptor phase, and sample volume, were investigated and optimized. After optimization, the linearity range of 0.5-250.0 µg L^-1 and detection limits of 0.2-1.0 µg L^-1 were obtained for the analytes. The extraction recovery values and preconcentration factors were 10.7-55.3% and 16-83, respectively. The presence of polyaniline in the composition of the nanofibers significantly improved the extraction efficiency of the polar acidic drugs due to providing the possibility of various interactions with the target analytes such as hydrogen bonding, π-stacking, and anion exchange. The obtained results demonstrate the excellent efficiency of the synthesized electrospun nanofibrous mat as a novel support membrane for immobilizing 1-octanol and as an interactive substrate for electromembrane extraction of acidic polar drugs. Eventually, the proposed on-chip EME method exhibits acceptable precision (relative standard deviations less than 9.7% (n = 3)) and good accuracy (86-112%) for determining the target analytes in the plasma samples.

Piezoelectric conductive electrospun nanocomposite PCL/Polyaniline/Barium Titanate scaffold for tissue engineering applications

Recent trends in tissue engineering technology have switched to electrical potentials generated through bioactive scaffolds regarding their appropriate effects on cell behaviors. Preparing a piezo-electrical stimuli scaffold with high electrical conductivity for bone and cartilage tissue regeneration is the ultimate goal of the present study. Here, Barium Titanate nanoparticles (BaTiO₃ NPs) were used as piezoelectric material and highly conductive binary doped Polyaniline nanoparticles (PANI NPs) were synthesized by oxidative polymerization. Polycaprolactone (PCL) was applied as carrier substrate polymer and conductive spun nanofibrous scaffolds of PCL/PANI composites were prepared in two different amounts of PANI (3 and 5 wt.%). The conductivity of PCL/PANI nanofibers has been analyzed by standard four probes test. Based on the obtained results, the PCL/PANI5 (with 5 wt.% PANI) was selected due to the superior electrical conductivity of 8.06 × 10^-4 s cm ^- 1. Moreover, the piezoelectric nanofibrous scaffolds of PCL/BT composite were electrospun in three different amounts of BT (20, 30, and 40 wt.%). To investigate the synergic effect of conductive PANI and piezoelectric BT, ternary nanocomposite scaffolds of PCL/PANI/BT were prepared using the dual jet electrospinning technique. The piezoelectric properties have been analyzed by determining the produced voltage. The morphological assessment, contact angle, mechanical test, and MTT assay have been conducted to evaluate other properties including biocompatibility of nanofibrous scaffolds. The PCL/PANI5/BT40 composite resulted in an unprecedented voltage of 1.9 Volt. SEM results confirm that BT NPs have been distributed and embedded inside PCL fibers quite appropriately. Also, the chosen scaffolds were homogeneously intertwined and possessed an average fiber diameter of 288 ± 180 nm, and a contact angle of 92 ± 7°, making it a desirable surface for cell attachment and protein interactions. Moreover, Young's modulus, ultimate tensile stress, and elongation were obtained as 11 ± 1 MPa, 5 ± 0.6 MPa, and 109 ± 15% respectively. Obtained results assert the novel potential of piezo-electrical stimuli conductive nanocomposite scaffold for tissue engineering applications.

Conductive Polymeric-Based Electroactive Scaffolds for Tissue Engineering Applications: Current Progress and Challenges from Biomaterials and Manufacturing Perspectives

The practice of combining external stimulation therapy alongside stimuli-responsive bio-scaffolds has shown massive potential for tissue engineering applications. One promising example is the combination of electrical stimulation (ES) and electroactive scaffolds because ES could enhance cell adhesion and proliferation as well as modulating cellular specialization. Even though electroactive scaffolds have the potential to revolutionize the field of tissue engineering due to their ability to distribute ES directly to the target tissues, the development of effective electroactive scaffolds with specific properties remains a major issue in their practical uses. Conductive polymers (CPs) offer ease of modification that allows for tailoring the scaffold's various properties, making them an attractive option for conductive component in electroactive scaffolds. This review provides an up-to-date narrative of the progress of CPs-based electroactive scaffolds and the challenge of their use in various tissue engineering applications from biomaterials perspectives. The general issues with CP-based scaffolds relevant to its application as electroactive scaffolds were discussed, followed by a more specific discussion in their applications for specific tissues, including bone, nerve, skin, skeletal muscle and cardiac muscle scaffolds. Furthermore, this review also highlighted the importance of the manufacturing process relative to the scaffold's performance, with particular emphasis on additive manufacturing, and various strategies to overcome the CPs' limitations in the development of electroactive scaffolds.

Plasma and Polymers: Recent Progress and Trends

Plasma-enhanced synthesis and modification of polymers is a field that continues to expand and become increasingly more sophisticated. The highly reactive processing environments afforded by the inherently dynamic nature of plasma media are often superior to ambient or thermal environments, offering substantial advantages over other processing methods. The fluxes of energy and matter toward the surface enable rapid and efficient processing, whereas the charged nature of plasma-generated particles provides a means for their control. The range of materials that can be treated by plasmas is incredibly broad, spanning pure polymers, polymer-metal, polymer-wood, polymer-nanocarbon composites, and others. In this review, we briefly outline some of the recent examples of the state-of-the-art in the plasma-based polymer treatment and functionalization techniques.