Development and bioevaluation of nanofibers with blood-derived growth factors for dermal wound healing

Recombinant human epidermal growth factor-loaded liposomes and transferosomes for dermal delivery: Development, characterization, and cytotoxicity evaluation

Recombinant human epidermal growth factor (rhEGF) is widely utilized as an antiaging compound in wound-healing therapies and cosmetic purposes. However, topical administration of rhEGF has limited treatment outcomes because of its poor percutaneous penetration and rapid proteinase degradation. To overcome these obstacles, this study aims to develop and characterize rhEGF-containing conventional liposomes (rhEGF-CLs) and transferosomes (rhEGF-TFs) as efficient dermal carriers. Physicochemical characterization such as particle size, zeta potential (ZP), morphology, encapsulation efficiency (EE%), and release properties of nanocarriers as well as in vitro cytotoxicity in human dermal fibroblast (HDF) and human embryonic kidney (HEK293) cell lines were investigated. rhEGF-TFs at the rhEGF concentration ranging from 0.05 to 1.0 μg/mL were chosen as the optimum formulation due to the desired release profile, acceptable EE%, optimal cell proliferation, and minimal cytotoxicity compared to the control and free rhEGF. However, higher concentrations caused a decrease in cell viability. The ratio 20:80 of Tween 80 to lipid was optimal for rhEGF-TFs-2, which had an average diameter of 233.23 ± 2.64 nm, polydispersity index of 0.33 ± 0.05, ZP of -15.46 ± 0.29 mV, and EE% of 60.50 ± 1.91. The formulations remained stable at 5°C for at least 1 month. TEM and SEM microscopy revealed that rhEGF-TFs-2 had a regular shape and unilamellar structure. In vitro drug release studies confirmed the superiority of rhEGF-TFs-2 in terms of optimal cumulative release of rhEGF approximately 82% within 24 h. Franz diffusion cell study showed higher rhEGF-TFs-2 skin permeation compared to free rhEGF solution. Taken together, we concluded that rhEGF-TFs can be used as a promising formulation for wound healing and skin regeneration products.

PRP of T2DM Patient Immobilized on PCL Nanofibers Stimulate Endothelial Cells Proliferation

Diabetic foot ulcers (DFU) are a common complication of Type 2 Diabetes Mellitus (T2DM). Development of bioactive wound healing covers is an important task in medicine. The use of autologous platelet-rich plasma (PRP) consisting of growth factors, cytokines and components of extracellular matrix is a perspective approach for DFU treatment, but we previously found that some T2DM PRP samples have a toxic effect on mesenchymal stem cells (MSCs) in vitro. Here, we covalently immobilized T2DM PRP proteins on polycaprolactone (PCL) nanofibers, and the growth of endothelial cells on the PCL-COOH-PRP was investigated. Additionally, the level of NO reflecting the cytotoxic effects of PRP, angiogenin, and VEGF levels were measured in T2DM PRP samples. The results showed that the application of PCL-COOH-PRP nanofibers allows to remove the cytotoxicity of T2DM PRP and to improve endothelial cell adhesion and proliferative activity. We showed that the origin of T2DM PRP (the level of PRP toxicity or presence/absence of DFU) does not influence the efficiency of cell growth on PCL-COOH-PRP, and on the level of angiogenin, vascular epidermal growth factor (VEGF) in PRP itself.

Scientometric Research on Trend Analysis of Nano-Based Sustained Drug Release Systems for Wound Healing

Nanomaterials, such as the nanoparticle (NP), nanomicelle, nanoscaffold, and nano-hydrogel, have been researched as nanocarriers for drug delivery more and more recently. Nano-based drug sustained release systems (NDSRSs) have been used in many medical fields, especially wound healing. However, as we know, no scientometric analysis has been seen on applying NDSRSs in wound healing, which could be of great importance to the relevant researchers. This study collected publications from 1999 to 2022 related to NDSRSs in wound healing from the Web of Science Core Collection (WOSCC) database. We employed scientometric methods to comprehensively analyze the dataset from different perspectives using CiteSpace, VOSviewer, and Bibliometrix. The results indicated that China published the most significant number of documents in the last two decades, Islamic Azad Univ was the most productive institution, and Jayakumar, R was the most influential author. Regarding the analysis of keywords, trend topics indicate that "antibacterial", "chitosan (CS)", "scaffold", "hydrogel", "silver nanoparticle", and "growth factors (GFs)" are the hot topics in recent years. We anticipate that our work will provide a comprehensive overview of research in this field and help scholars better understand the research hotspots and frontiers in this area, thus inspiring further explorations in the future.

Recent advancement of nanotherapeutics in accelerating chronic wound healing process for surgical wounds and diabetic ulcers

One of the greatest challenges faced during surgical procedures is closing and healing of wounds, which are essential in the field of orthopaedics, trauma, intensive care and general surgery. One of the main causes of death has been linked to chronic wounds, especially in immunosuppressant or diabetic patients. Due to increasing chronic wound fatality along with different pathologies associated with them, the current therapeutic methods are insufficient which has established an eminent need for innovative techniques. Traditionally, wound healing was carried out using formulations and ointments containing silver combined with different biomaterial, but was found to be toxic. Hence, the advent of alternative nanomaterial-based therapeutics for effective wound healing have come into existence. In this review, we have discussed an overview of wound infections such as different wound types, the wound healing process, dressing of wounds and conventional therapies. Furthermore, we have explored various nanotechnological advances made in wound healing therapy which include the use of promising candidates such as organic, inorganic, hybrid nanoparticles/nanocomposites and synthetic/natural polymer-based nanofibers. This review further highlights nanomaterial-based applications for regeneration of tissue in wound healing and can provide a base for researchers worldwide to contribute to this advancing medical area of wound therapy.

Synthetic electrospun nanofibers as a supportive matrix in osteogenic differentiation of induced pluripotent stem cells

Continuous remodeling is not able to repair large bone defects. Bone tissue engineering is aimed to repair these defects by creating bone grafts. To do this, several technologies and biomaterials have been employed to fabricate an in vivo-like supportive matrix. Electrospinning is a versatile technique to fabricate porous matrices with interconnected pores and high surface area, replicating in vivo microenvironment. Electrospun scaffolds have been used in a large number of studies to provide a matrix for bone regeneration and osteogenic differentiation of stem cells such as induced pluripotent stem cells (iPSCs). Electrospinning uses both natural and synthetic polymers, either alone or in combination, to fabricate scaffolds. Among them, synthetic polymers have had a great promise in bone regeneration and repair. They allow the fabrication of biocompatible and biodegradable scaffolds with high mechanical properties, suitable for bone engineering. Furthermore, several attempts have done to increase the osteogenic properties of these scaffolds. This paper reviewed the potential of synthetic electrospun scaffolds in osteogenic differentiation of iPSCs. In addition, the approaches to improve the osteogenic differentiation of these scaffolds are addressed.

Precision-engineered niche for directed differentiation of MSCs to lineage-restricted mineralized tissues

The major difference between tissue healing and regeneration is the extent of instructional cues available to precisely direct the biological response. A classic example is reparative or osteodentin that is seen in response to physicochemical injury to the pulp-dentin complex. Dentin regeneration can direct the differentiation of dental stem cells using concerted actions of both soluble (biomolecules, agonists, and antagonists) and insoluble (matrix topology) cues. The major purpose of this study was to examine the synergistic combination of two discrete biomaterial approaches by utilizing nanofiber scaffolds in discrete configurations (aligned or random) with incorporated polymeric microspheres capable of controlled release of growth factors. Further, to ensure appropriate disinfection for clinical use, Radio-Frequency Glow Discharge (RFGD) treatments were utilized, followed by seeding with a mesenchymal stem cell (MSC) line. SEM analysis revealed electrospinning generated controlled architectural features that significantly improved MSC adhesion and proliferation on the aligned nanofiber scaffolds compared to randomly oriented scaffolds. These responses were further enhanced by RFGD pre-treatments. These enhanced cell adhesion and proliferative responses could be attributed to matrix-induced Wnt signaling that was abrogated by pre-treatments with anti-Wnt3a neutralizing antibodies. Next, we incorporated controlled-release microspheres within these electrospun scaffolds with either TGF-β1 or BMP4. We observed that these scaffolds could selectively induce dentinogenic or osteogenic markers (DSPP, Runx2, and BSP) and mineralization. This work demonstrates the utility of a novel, modular combinatorial scaffold system capable of lineage-restricted differentiation into bone or dentin. Future validation of this scaffold system in vivo as a pulp capping agent represents an innovative dentin regenerative approach capable of preserving tooth pulp vitality.

Treatment of Scars with Laser-Assisted Delivery of Growth Factors and Vitamin C: A Comparative, Randomised, Double-blind, Early Clinical Trial

BACKGROUND

Scarring can jeopardize the final result of plastic surgeries. Deep dermal injuries activate dermal fibroblasts that produce excessive amount of collagen and inflammatory cytokines and growth factors, which contributes to increased fibrous tissue and scarring tissue formation.

OBJECTIVES

The aim of this early study, double-blind, prospective, randomised clinical trial was to investigate the use of laser-assisted drug delivery (LADD) for scar improvement to support the establishment of LADD as standard therapy modality and to indicate suitable drugs for dermal administration.

MATERIAL AND METHODS

In total, 132 patients seeking scar treatment were consented and randomised. The control group (64 patients) received laser resurfacing immediately followed by skin surface application of Vitamin C and 68 patients received laser treatment followed by skin surface application of a cosmeceutical containing growth factors (GFs) and Vitamin C. Photographs were obtained before and three months after the procedure and submitted to three-dimensional reconstruction by the software Dermapix^®. Objective measurements provided by the software were statistically analysed and established the differences in the treatment result between the two groups.

RESULTS

There was a significant reduction in scar roughness and volume in both groups (p < 0.01). Mann-Whitney test confirmed that the group treated vitamin C and GFs presented significantly better results than the group treated with vitamin C alone (p < 0.01).

CONCLUSION

LADD has proven efficient as scars were reduced in both study groups. Furthermore, the addition of growth factors provided statistically significant better outcomes and resulted in more inconspicuous scars. No adverse reactions were observed.

CLINICAL TRIAL REGISTRATION

Plataforma Brasil under the number CAAE: 63710716.2.0000.5664.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Rationally design of electrospun polysaccharides polymeric nanofiber webs by various tools for biomedical applications: A review

Nanofibers have a particular benefit when delivering a spectrum of therapeutic drugs for diverse biomedical applications. Nanofibers are easily fabricated from cellulose acetate, chitosan, polycaprolactone, and other polymers with regulated morphology and release profiles due to nanotechnology's recent advancement. This review will provide the latest approaches to the fabrication of electrospun nanofibers containing herbal extracts, antimicrobial peptides, and antibiotics for wound-healing potential. Besides, synthesis and evaluation of nanofibrous mats, including conducting polymer and evaluate their possibility for wound healing. In addition, nanofibers are loaded with some drugs for skin cancer treatment and contain growth factors for tissue regeneration. Also, the current two-dimensional nanofibers limitations and the various techniques for convert two-dimensional to three-dimension nanofibers to avoid these drawbacks. Moreover, the future direction in improving the three-dimensional structure and functionality has been including.

Treatment challenges and delivery systems in immunomodulation and probiotic therapies for periodontitis

Introduction: Periodontitis is a widespread illness that arises due to disrupted interplay between the oral microbiota and the host immune response. In some cases, conventional therapies can provide temporary remission, although this is often followed by disease relapse. Recent studies of periodontitis pathology have promoted the development of new therapeutics to improve treatment options, together with local application using advanced drug delivery systems.Areas covered: This paper provides a critical review of the status of current treatment approaches to periodontitis, with a focus on promising immunomodulation and probiotic therapies. These are based on delivery of small molecules, peptides, proteins, DNA or RNA, and probiotics. The key findings on novel treatment strategies and formulation of advanced delivery systems, such as nanoparticles and nanofibers, are highlighted.Expert opinion: Multitarget therapy based on antimicrobial, immunomodulatory, and probiotic active ingredients incorporated into advanced delivery systems for application to the periodontal pocket can improve periodontitis treatment outcomes. Translation of such adjuvant therapy from laboratory to patient is expected in the future.

Cellular Response to Individual Components of the Platelet Concentrate

Platelet concentrates and especially their further product platelet lysate, are widely used as a replacement for cell culturing. Platelets contain a broad spectrum of growth factors and bioactive molecules that affect cellular fate. However, the cellular response to individual components of the human platelet concentrate is still unclear. The aim of this study was to observe cellular behavior according to the individual components of platelet concentrates. The bioactive molecule content was determined. The cells were supplemented with a medium containing 8% (v/v) of platelet proteins in plasma, pure platelet proteins in deionized water, and pure plasma. The results showed a higher concentration of fibrinogen, albumin, insulin growth factor I (IGF-1), keratinocyte growth factor (KGF), and hepatocyte growth factor (HGF), in the groups containing plasma. On the other hand, chemokine RANTES and platelet-derived growth factor bb (PDGF-bb), were higher in the groups containing platelet proteins. The groups containing both plasma and plasma proteins showed the most pronounced proliferation and viability of mesenchymal stem cells and fibroblasts. The platelet proteins alone were not sufficient to provide optimal cell growth and viability. A synergic effect of platelet proteins and plasma was observed. The data indicated the importance of plasma in platelet lysate for cell growth.

Three dimensional nanofibrous and compressible poly(L-lactic acid) bone grafts loaded with platelet-rich plasma

In this study, nanofibrous matrices of poly(L-lactic acid)-hydroxyapatite (PLLA-HAp) were successfully fabricated by three-dimensional (3D) electrospinning for use in the treatment of irregular bone damages. Compressibility analysis showed that 3D nanofibrous grafts occupied at least 2-fold more volume than their 2D form and they can easily take shape of the defect zone with irregular geometry. Moreover, the compression moduli of the PLLA and PLLA-HAp grafts were calculated as 8.0 ± 3.0 kPa and 11.8 ± 3.9 kPa, respectively, while the strain values of the same samples at the maximum load of 600 kPa were 164 ± 28% and 130 ± 20%, respectively. Treatment of the grafts with aqueous sodium hydroxide solution increased the surface roughness and thus the alloplastic graft materials (PLLA-HAp/M) protecting the fiber morphology were produced successfully. Then, platelet-rich plasma (PRP) was loaded into the surface modified grafts and activated with 10% calcium chloride. The efficiency of the activation was evaluated with flow cytometry and it was found that after activation the percentages of CD62 (P-selectin) and CD41/61 (glycoprotein IIb/IIIa) proteins increased approximately 4-fold. Surface hydrophilicity and biological activity of the PLLA-HAp grafts were enhanced by fibrin coating after PRP activation. Thein vitrocell culture studies which were carried out by using mouse pre-osteoblasts (MC3T3-E1) showed that graft materials supported by PRP increased cellular proliferation and osteogenic differentiation significantly. Thein vivoresults demonstrated that compared with bare PLLA-HAp/M grafts, the PRP loaded grafts (PRP-PLLA-HAp/M) induced significantly greater bone formation based on computed tomography, histological and immunohistochemical analyses. Our findings suggest that 3D PLLA nanofibrous matrices can be used as a graft material for irregular bone defects especially when combined with PRP as an osteogenic induction agent.

Bilayered Fibrin-Based Electrospun-Sprayed Scaffold Loaded with Platelet Lysate Enhances Wound Healing in a Diabetic Mouse Model

The present study examined the effects of a bilayered fibrin/poly(ether)urethane scaffold loaded with platelet lysate by a combination of electrospinning and spray, phase-inversion method for wound healing. In particular, the poly(ether)urethane layer was obtained using by a spray phase-inversion method and the fibrin fibers network were loaded with platelet lysate by electrospinning. The kinetics release and the bioactivity of growth factors released from platelet lysate-scaffold were investigated by ELISA and cell proliferation test using mouse fibroblasts, respectively. The in-vitro experiments demonstrated that a bilayered fibrin/poly(ether)urethane scaffold loaded with platelet lysate provides a sustained release of bioactive platelet-derived growth factors. The effect of a bilayered fibrin/poly(ether)urethane scaffold loaded with platelet lysate on wound healing in diabetic mouse (db/db) was also investigated. The application of the scaffold on full-thickness skin wounds significantly accelerated wound closure at day 14 post-surgery when compared to scaffold without platelet lysates or commercially available polyurethane film, and at the same level of growth factor-loaded scaffold. Histological analysis demonstrated an increased re-epithelialization and collagen deposition in platelet lysate and growth factor loaded scaffolds. The ability of bilayered fibrin/poly(ether)urethane scaffold loaded with platelet lysate to promote in-vivo wound healing suggests its usefulness in clinical treatment of diabetic ulcers.

Bioactive Medications for the Delivery of Platelet Derivatives to Skin Wounds

Chronic wounds are the result of alterations in the complex series of events of physiological wound healing. In particular, the prolonged inflammation results in increased protease activity, in the deg-radation of extracellular matrix (ECM) and of growth factors (GFs). The relevance of platelet GFs in maintaining and restoring the complex equilibrium of different moments in wound healing is well recog-nized. Moreover, the observed decrease of their levels in chronic wounds suggested a possible therapeutic role of the external application to the wounds. It has been also pointed out that tissue regeneration can be more efficiently obtained by the synergic use of different GFs. Platelet derivatives such as platelet-rich plasma (PRP) and platelet lysate (PL) are able to release GFs in a balanced pool. Their therapeutic use in regenerative medicine and wound healing has been therefore more and more frequently proposed in clini-cal trials and in the literature. The development of a suitable formulation able to control the GFs release rate, to protect the GFs, and to assure their prolonged contact with the wound site, is of paramount im-portance for the therapeutic success. The present review considers some formulation approaches for PRP and PL application to wounds

Core-shell nanofibers as drug delivery systems

Core-shell nanofibers have grown in popularity over the last decade owing to their special features and their many applications in biomedicine. They can be produced by electrospinning of immiscible polymer blends or emulsions through a single nozzle or by electrospinning using a coaxial nozzle. Several of the electrospinning parameters allow great versatility for the compositions and diameters of core-shell nanofibers to be produced. Morphology of core-shell nanofibers can be investigated using transmission electron microscopy and, in some cases, scanning electron microscopy. Several studies have shown that core-shell nanofibers have some advantages over monolithic nanofibers, such as better drug, protein, gene or probiotic incorporation into the nanofibers, greater control over drug release, and maintenance of protein structure and activity during electrospinning. We herein review the production and characterization of core-shell nanofibers, the critical parameters that affect their development, and their advantages as delivery systems.

Effect of Solution Composition Variables on Electrospun Alginate Nanofibers: Response Surface Analysis

Alginate is a promising biocompatible and biodegradable polymer for production of nanofibers for drug delivery and tissue engineering. However, alginate is difficult to electrospin due to its polyelectrolyte nature. The aim was to improve the 'electrospinability' of alginate with addition of exceptionally high molecular weight poly(ethylene oxide) (PEO) as a co-polymer. The compositions of the polymer-blend solutions for electrospinning were varied for PEO molecular weight, total (alginate plus PEO) polymer concentration, and PEO proportion in the dry alginate-PEO polymer mix used. These were tested for rheology (viscosity, complex viscosity, storage and loss moduli) and conductivity, and the electrospun nanofibers were characterized by scanning electron microscopy. One-parameter-at-a-time approach and response surface methodology (RSM) were used to optimize the polymer-blend solution composition to obtain defined nanofibers. Both approaches revealed that the major influence on nanofiber formation and diameter were total polymer concentration and PEO proportion. These polymer-blend solutions of appropriate conductivity and viscosity enabled fine-tuning of nanofiber diameter. PEO molecular weight of 2-4 million Da greatly improved the electrospinnability of alginate, producing nanofibers with >85% alginate. This study shows that RSM can be used to design nanofibers with optimal alginate and co-polymer contents to provide efficient scaffold material for regenerative medicine.

A green approach to obtain stable and hydrophilic cellulose-based electrospun nanofibrous substrates for sustained release of therapeutic molecules

Stable and (bio)-compatible nanofibrous matrices showing effective incorporation and release of nonsteroidal anti-inflammatory drugs (NSAIDs) hold a huge potential in tissue regeneration and wound healing.

Needleless electrospun and centrifugal spun poly-ε-caprolactone scaffolds as a carrier for platelets in tissue engineering applications: A comparative study with hMSCs

The biofunctionalization of scaffolds for tissue engineering is crucial to improve the results of regenerative therapies. This study compared the effect of platelet-functionalization of 2D electrospun and 3D centrifugal spun scaffolds on the osteogenic potential of hMSCs. Scaffolds prepared from poly-ε-caprolactone, using electrospinning and centrifugal spinning technology, were functionalized using five different concentrations of platelets. Cell proliferation, metabolic activity and osteogenic differentiation were tested using hMSCs cultured in differential and non-differential medium. The porous 3D structure of the centrifugal spun fibers resulted in higher cell proliferation. Furthermore, the functionalization of the scaffolds with platelets resulted in a dose-dependent increase in cell metabolic activity, proliferation and production of an osteogenic marker - alkaline phosphatase. The effect was further promoted by culture in an osteogenic differential medium. The increase in combination of both platelets and osteogenic media shows an improved osteoinduction by platelets in environments rich in inorganic phosphate and ascorbate. Nevertheless, the results of the study showed that the optimal concentration of platelets for induction of hMSC osteogenesis is in the range of 900-3000 × 10⁹ platelets/L. The study determines the potential of electrospun and centrifugal spun fibers with adhered platelets, for use in bone tissue engineering.

Deformable liposomes for skin therapy with human epidermal growth factor: The effect of liposomal surface charge

The topical administration of exogenous human epidermal growth factor (hEGF) is a promising approach for improved chronic wound therapy. To develop therapeutically superior hEGF formulation, we prepared hEGF-containing neutral (NDLs), cationic (CDLs) and anionic (ADLs) deformable liposomes (DLs), respectively, since it is expected that the liposomal surface charge can affect both the liposomal physicochemical properties, their skin penetration potential and therapeutic efficacy of liposome-associated drug. All prepared liposomes were of similar size (300-350 nm) with high hEGF load (~80% entrapment efficacy). Among the studied DLs, ADLs were found to be most promising for sustained release of hEGF, as assessed in vitro using the polyamide membrane. Ex vivo studies revealed that all DLs were excellent systems for skin therapy with hEGF and no penetration of hEGF through the full thickness human skin was detected. ADLs provided a depot exhibiting the highest hEGF retention onto the human skin surface. ADLs also revealed enhanced mitogenic activities in human fibroblasts compared to both NDLs and CDLs after 48 hrs treatment. Moreover, hEGF-containing ADLs significantly enhanced mitogenic activity in fibroblast as compared to activity of hEGF solution (positive control). Similar trends were observed in human keratinocytes after 24 hrs of treatment. We proved that the liposomal surface charge affects the therapeutic potential of hEGF-containing liposomes. hEGF-containing ADLs can be a promising nanosystem-based formulation for localized therapy of chronic wounds.

Electrospun polymeric nanofibres as wound dressings: A review

Skin wounds have significant morbidity and mortality rates associated. This is explained by the limited effectiveness of the currently available treatments, which in some cases do not allow the reestablishment of the structure and functions of the damaged skin, leading to wound infection and dehydration. These drawbacks may have an impact on the healing process and ultimately prompt patients' death. For this reason, researchers are currently developing new wound dressings that enhance skin regeneration. Among them, electrospun polymeric nanofibres have been regarded as promising tools for improving skin regeneration due to their structural similarity with the extracellular matrix of normal skin, capacity to promote cell growth and proliferation and bactericidal activity as well as suitability to deliver bioactive molecules to the wound site. In this review, an overview of the recent studies concerning the production and evaluation of electrospun polymeric nanofibrous membranes for skin regenerative purposes is provided. Moreover, the current challenges and future perspectives of electrospun nanofibrous membranes suitable for this biomedical application are highlighted.

Nanomedicines and gene therapy for the delivery of growth factors to improve perfusion and oxygenation in wound healing

Oxygen plays a key role in wound healing, and hypoxia is a major cause of wound healing impairment; therefore, treatments to improve hemodynamics and increase wound oxygenation are of particular interest for the treatment of chronic wounds. This article describes the roles of oxygen and angiogenesis in wound healing as well as the tools used to evaluate tissue oxygenation and perfusion and then presents a review of nanomedicines and gene therapies designed to improve perfusion and oxygenation and accelerate wound healing.

Blood derivatives awaken in regenerative medicine strategies to modulate wound healing

Blood components play key roles in the modulation of the wound healing process and, together with the provisional fibrin matrix ability to selectively bind bioactive molecules and control its spatial-temporal presentation, define the complex microenvironment that characterize this biological process. As a biomimetic approach, the use of blood derivatives in regenerative strategies has awakened as a source of multiple therapeutic biomolecules. Nevertheless, and despite their clinical relevance, blood derivatives have been showing inconsistent therapeutic results due to several factors, including proper control over their delivery mechanisms. Herein, we highlight recent trends on the use biomaterials to protect, sequester and deliver these pools of biomolecules in tissue engineering and regenerative medicine approaches. Particular emphasis is given to strategies that enable to control their spatiotemporal delivery and improve the selectivity of presentation profiles of the biomolecules derived from blood derivatives rich in platelets. Finally, we discussed possible directions for biomaterials design to potentiate the aimed regenerative effects of blood derivatives and achieve efficient therapies.

Biomaterials for Skin Substitutes

Patients with extensive burns rely on the use of tissue engineered skin due to a lack of sufficient donor tissue, but it is a challenge to identify reliable and economical scaffold materials and donor cell sources for the generation of a functional skin substitute. The current review attempts to evaluate the performance of the wide range of biomaterials available for generating skin substitutes, including both natural biopolymers and synthetic polymers, in terms of tissue response and potential for use in the operating room. Natural biopolymers display an improved cell response, while synthetic polymers provide better control over chemical composition and mechanical properties. It is suggested that not one material meets all the requirements for a skin substitute. Rather, a composite scaffold fabricated from both natural and synthetic biomaterials may allow for the generation of skin substitutes that meet all clinical requirements including a tailored wound size and type, the degree of burn, the patient age, and the available preparation technique. This review aims to be a valuable directory for researchers in the field to find the optimal material or combination of materials based on their specific application.

Application of response surface methodology to tailor the surface chemistry of electrospun chitosan-poly(ethylene oxide) fibers

Chitosan is a promising biocompatible polymer for regenerative engineering applications, but its processing remains challenging due to limited solubility and rigid crystalline structure. This work represents the development of electrospun chitosan/poly(ethylene oxide) blend nanofibrous membranes by means of a numerical analysis in order to identify and tailor the main influencing parameters with respect to accessible surface nitrogen functionalities which are of importance for the biological activity as well as for further functionalization. Depending on the solution composition, both gradient fibers and homogenous blended fiber structures could be obtained with surface nitrogen concentrations varying between 0 and 6.4%. Response surface methodology (RSM) revealed chitosan/poly(ethylene oxide) ratio and chitosan molecular weight as the main influencing factors with respect to accessible nitrogen surface atoms and respective concentrations. The model showed good adequacy hence providing a tool to tailor the surface properties of chitosan/poly(ethylene oxide) blends by addressing the amount of accessible chitosan.

Imparting Pharmaceutical Applications to the Surface of Fabrics for Wound and Skin Care by Ultrasonic Waves

In this review, we report the functionalization of textiles composed of nanoscale reactive materials in the treatment of wounds and skin diseases such as acne. In view of the growing demand for high-quality textiles, much research is focused on the creation of antimicrobial finishings for fabrics, in order to protect customers from pathogenic or odorgenerating microorganisms. We present coatings from inorganic, organic and biochemical nanoparticles (NPs) on surfaces that impart the ability to kill bacteria, avoid biofilm formation and speed up the recovery of wounds. In all three cases, sonochemistry is used for immobilizing the nanoparticles on the surfaces. The Introduction broadly covers the progress of nanotechnology in the fields of wound and skin care. The first section of this review outlines the mechanism of the ultrasound-assisted deposition of nanoparticles on textiles. The coating can be performed by an in-situ process in which the nanoparticles are formed and subsequently thrown onto the surface of the fabrics at a very high speed. This approach was used in depositing metal-oxide NPs such as ZnO, CuO and Zn-CuO or the organic NPs of tannic acid, chitosan, etc. on textiles. In addition, the sonochemical process can be used as a "throwing stone" technique, namely, previously synthesized or commercially purchased NPs can be placed in the sonication bath and sonicated in the presence of the fabric. The collapse of the acoustic bubble in the solution causes the throwing of the immersed commercial NPs onto the textiles. This section will also outline why sonochemical deposition on textiles is considered the best coating technique. The second section will discuss new applications of the sonochemically- coated textiles in killing bacteria, avoiding biofilm formation and more. Two points should be noted: 1) the review will primarily report results obtained at Bar-Ilan University and 2) since for all textiles tested in our experiments (cotton, polyester, nylon, nonwoven) similar results were obtained, the type of textile used in a specific experiment will not be mentioned - textiles will be discussed in general. It is also worth emphasizing that this review concentrates only on the sonochemical coating of textiles, ignoring other deposition techniques.

Immobilization of Platelet-Rich Plasma onto COOH Plasma-Coated PCL Nanofibers Boost Viability and Proliferation of Human Mesenchymal Stem Cells

The scaffolds made of polycaprolactone (PCL) are actively employed in different areas of biology and medicine, especially in tissue engineering. However, the usage of unmodified PCL is significantly restricted by the hydrophobicity of its surface, due to the fact that its inert surface hinders the adhesion of cells and the cell interactions on PCL surface. In this work, the surface of PCL nanofibers is modified by Ar/CO₂/C₂H₄ plasma depositing active COOH groups in the amount of 0.57 at % that were later used for the immobilization of platelet-rich plasma (PRP). The modification of PCL nanofibers significantly enhances the viability and proliferation (by hundred times) of human mesenchymal stem cells, and decreases apoptotic cell death to a normal level. According to X-ray photoelectron spectroscopy (XPS), after immobilization of PRP, up to 10.7 at % of nitrogen was incorporated into the nanofibers surface confirming the grafting of proteins. Active proliferation and sustaining the cell viability on nanofibers with immobilized PRP led to an average number of cells of 258 ± 12.9 and 364 ± 34.5 for nanofibers with ionic and covalent bonding of PRP, respectively. Hence, our new method for the modification of PCL nanofibers with PRP opens new possibilities for its application in tissue engineering.

Functional electrospun fibers for the treatment of human skin wounds

Wounds are trauma induced defects of the human skin involving a multitude of endogenous biochemical events and cellular reactions of the immune system. The healing process is extremely complex and affected by the patient's physiological conditions, potential implications like infectious pathogens and inflammation as well as external factors. Due to increasing incidence of chronic wounds and proceeding resistance of infection pathogens, there is a strong need for effective therapeutic wound care. In this context, electrospun fibers with diameters in the nano- to micrometer range gain increasing interest. While resembling the structure of the native human extracellular matrix, such fiber mats provide physical and mechanical protection (including protection against bacterial invasion). At the same time, the fibers allow for gas exchange and prevent occlusion of the wound bed, thus facilitating wound healing. In addition, drugs can be incorporated within such fiber mats and their release can be adjusted by the material and dimensions of the individual fibers. The review gives a comprehensive overview about the current state of electrospun fibers for therapeutic application on skin wounds. Different materials as well as fabrication techniques are introduced including approaches for incorporation of drugs into or drug attachment onto the fiber surface. Against the background of wound pathophysiology and established therapy approaches, the therapeutic potential of electrospun fiber systems is discussed. A specific focus is set on interactions of fibers with skin cells/tissues as well as wound pathogens and strategies to modify and control them as key aspects for developing effective wound therapeutics. Further, advantages and limitations of controlled drug delivery from fiber mats to skin wounds are discussed and a future perspective is provided.

A comparison of high throughput core–shell 2D electrospinning and 3D centrifugal spinning techniques to produce platelet lyophilisate-loaded fibrous scaffolds and their effects on skin cells

Nanofibres enriched with bioactive molecules, as actively acting scaffolds, play an important role in tissue engineering.

Drug delivery systems for wound healing

Protein, gene, and small molecule therapies hold great potential for facilitating comprehensive tissue repair and regeneration. However, their clinical value will rely on effective delivery systems which maximize their therapeutic benefit. Significant advances have been made in recent years towards biomaterial delivery systems to satisfy this clinical need. Here we summarize the most outstanding advances in drug delivery technology for cutaneous wound healing.

Development of Suberin Fatty Acids and Chloramphenicol-Loaded Antimicrobial Electrospun Nanofibrous Mats Intended for Wound Therapy

Suberin fatty acids (SFAs) isolated from outer birch bark were investigated as an antimicrobial agent and biomaterial in nanofibrous mats intended for wound treatment. Electrospinning (ES) was used in preparing the composite nonwoven nanomats containing chloramphenicol (CAM; as a primary antimicrobial drug), SFAs, and polyvinylpyrrolidone (as a carrier polymer for ES). The X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, and texture analysis were used for the physicochemical and mechanical characterization of the nanomats. ES produced nanofibrous mats with uniform structure and with an average fiber diameter ranging from 370 to 425 nm. Microcrystalline SFAs and crystalline CAM were found to undergo a solid-state transformation during ES processing. The ES process caused also the loss of CAM in the final nanofibers. In the texture analysis, the SFAs containing nanofibers exhibited significantly higher maximum detachment force to an isolated pig skin (p < 0.05) than that obtained with the reference nanofibers. CAM exists in an amorphous form in the nanofibers which needs to be taken into account in controlling the physical storage stability. In conclusion, homogeneous composite nanofibrous mats for wound healing can be electrospun from the ternary mixture(s) of CAM, SFAs, and polyvinylpyrrolidone.

Organic Nanomaterials and Their Applications in the Treatment of Oral Diseases

There is a growing interest in the development of organic nanomaterials for biomedical applications. An increasing number of studies focus on the uses of nanomaterials with organic structure for regeneration of bone, cartilage, skin or dental tissues. Solid evidence has been found for several advantages of using natural or synthetic organic nanostructures in a wide variety of dental fields, from implantology, endodontics, and periodontics, to regenerative dentistry and wound healing. Most of the research is concentrated on nanoforms of chitosan, silk fibroin, synthetic polymers or their combinations, but new nanocomposites are constantly being developed. The present work reviews in detail current research on organic nanoparticles and their potential applications in the dental field.

Nanomaterials as a game changer in the management and treatment of diabetic foot ulcers

Nanoengineered biomaterials have tremendously improved the range of tools utilized for the control of as well as acceleration of healing of diabetic foot ulcers (DFU) over the last few decades.