Sol–gel processed mupirocin silica microspheres loaded collagen scaffold: A synergistic bio-composite for wound healing

Stimulation of macrophage cell lines confined with silica and/or silicon particles and embedded in structured collagen gels

Macrophages encapsulated in composite gels are subjected to a three-dimensional (3D) microenvironment and material-related stimuli that allow modulation of their phenotypes. Herein, 3D collagen fibrillar networks structured with di- or tri-functionalized oligourethanes, including Si-O or Si-Si particles confined therein, are compared regarding their physicochemical properties and material-guided macrophage activation. Gelation kinetics, degradation/swelling, and rheometric results demonstrated that the properties of the composite gels depend on the oligourethane functionalization number (derived from diols/triols and L-Lysine diisocyanate, LDI) and silica incorporation. Human or murine macrophages seeded or encapsulated in the composite gels showed good viability and the adoption of an anti-inflammatory phenotype in response to the silica in the composite gel, showing accelerated gelation when cell culture components are present in the liquid precursors. An increase in cell viability proportional to the storage modulus was observed. ELISA tests strongly suggest that the Si-Si nanoparticles in the composites can antagonize the pro-inflammatory stimulation with lipopolysaccharides (LPS) and interferon-gamma (IFNγ), even promoting an anti-inflammatory response in embedded cells after 24 h. Silicon-doped and crosslinked collagen gels have good potential to modulate macrophage inflammatory response, serving as a 3D immunomodulatory scaffold.

Collagen-Based Scaffolds for Volumetric Muscle Loss Regeneration

Volumetric muscle loss (VML) is a serious problem in healthcare that requires innovative solutions. Collagen and its derivatives are promising biomaterials for muscle tissue replacement due to their high biocompatibility, biodegradability, and lack of toxicity. This review comprehensively discusses collagen from various sources, its structural characteristics, cross-linking methods to obtain hydrogels, and approaches to incorporating various therapeutic molecules to create a biocomposite system with controlled release. Collagen-based scaffolds are promising constructs in tissue engineering and regenerative medicine. They can both perform their function independently and act as a depot for various biologically active substances (drugs, growth factors, genetic material, etc.). Collagen-based scaffolds for muscle volume restoration are three-dimensional constructs that support cell adhesion and proliferation and provide controlled release of therapeutic molecules. Various mechanical and biological properties of scaffolds can be achieved by cross-linking agents and bioactive molecules incorporated into the structure. This review highlights recent studies on collagen-based hydrogels for restoration of volumetric muscle loss.

Formulation, Optimization, and Evaluation of Non-Propellent Foam-Based Formulation for Burn Wounds Treatment

Burn injuries worldwide pose significant health risks due to frequent microbial infections, which worsen complications and increase mortality rates. The conventional antimicrobial formulations are available in the form of ointments and creams. These formulations are very greasy and stick to the clothes. The applications of these formulations by finger or applicator produce pain in the affected area and incur the possibility of microbial infection. To overcome these hurdles, authors developed a novel non-propellent foam (NPF) based formulation containing chlorhexidine for effective topical delivery. Initially, NPF containing Labrasol® (26.7%), sodium lauryl sulfate (1.2%), hydroxy propyl methyl cellulose (0.56%), butylated hydroxytoluene (0.1%), ethanol (1%), and distilled water was prepared and assessed for its consistency, and ability to form foam. The NPF was statistically optimized using the Box-Behnken design to determine the effect of polymer and surfactants on the critical foam properties. The optimized formulation showed a collapse time of 45 s with a unique nature of collapsing upon slight touch which is highly beneficial for burn patients with microbial infection. The diffusion study showed that more than 90% of the drug was released within 6 h. The skin permeation study showed that 23% of the total drug permeated through the skin after 6 h with 7.64 µg/cm2/h permeation flux. The developed formulation showed good antibacterial activity. The minimum inhibitory concentration of prepared NPF was found to be 2.5 µg/mL, 2.5 µg/mL, and 5.0 µg/mL against E. coli (MTCC-1687), P. aeruginosa (MTCC-1688), and S aureus (MTCC-737) respectively. The developed NPF formulation showed quick collapse time, excellent spreadability, good anti-bacterial activity, and a non-sticky nature representing a promising avenue for burn wound treatment without using any applicator.

Organic-inorganic biohybrid films from wool-keratin/jellyfish-collagen/silica/boron via sol-gel reactions for soft tissue engineering applications

Therapeutic angiogenesis is pivotal in creating effective tissue-engineered constructs that deliver nutrients and oxygen to surrounding cells. Hence, biomaterials that promote angiogenesis can enhance the efficacy of various medical treatments, encompassing tissue engineering, wound healing, and drug delivery systems. Considering these, we propose a rapid method for producing composite silicon-boron-wool keratin/jellyfish collagen (Si-B-WK/JFC) inorganic-organic biohybrid films using sol-gel reactions. In this approach, reactive tetraethyl orthosilicate and boric acid (pKa ⩾ 9.24) were used as silicon and boron sources, respectively, and a solid-state gel was formed through the condensation reaction of these reactive groups with the keratin/collagen mixture. Once the resulting gel was thoroughly suspended in water, the films were prepared by a casting/solvent evaporation methodology. The fabricated hybrid films were characterized structurally and mechanically. In addition, angiogenic characteristics were determined by the in ovo chick chorioallantoic membrane assay, which revealed an increased vascular network within the Si-B-WK/JFC biohybrid films. In conclusion, it is believed that Si-B-WK/JFC biohybrid films with mechanical and pro-angiogenic properties have the potential to be possessed in soft tissue engineering applications, especially wound healing.

Collagen-Based Scaffolds for Chronic Skin Wound Treatment

Chronic wounds, commonly known as ulcers, represent a significant challenge to public health, impacting millions of individuals every year and imposing a significant financial burden on the global health system. Chronic wounds result from the interruption of the natural wound-healing process due to internal and/or external factors, resulting in slow or nonexistent recovery. Conventional medical approaches are often inadequate to deal with chronic wounds, necessitating the exploration of new methods to facilitate rapid and effective healing. In recent years, regenerative medicine and tissue engineering have emerged as promising avenues to encourage tissue regeneration. These approaches aim to achieve anatomical and functional restoration of the affected area through polymeric components, such as scaffolds or hydrogels. This review explores collagen-based biomaterials as potential therapeutic interventions for skin chronic wounds, specifically focusing on infective and diabetic ulcers. Hence, the different approaches described are classified on an action-mechanism basis. Understanding the issues preventing chronic wound healing and identifying effective therapeutic alternatives could indicate the best way to optimize therapeutic units and to promote more direct and efficient healing.

Recent Advances in Collagen Antimicrobial Biomaterials for Tissue Engineering Applications: A Review

Biomaterial-based therapies have been receiving attention for treating microbial infections mainly to overcome the increasing number of drug-resistant bacterial strains and off-target impacts of therapeutic agents by conventional strategies. A fibrous, non-soluble protein, collagen, is one of the most studied biopolymers for the development of antimicrobial biomaterials owing to its superior physicochemical, biomechanical, and biological properties. In this study, we reviewed the different approaches used to develop collagen-based antimicrobial devices, such as non-pharmacological, antibiotic, metal oxide, antimicrobial peptide, herbal extract-based, and combination approaches, with a particular focus on preclinical studies that have been published in the last decade.

Biogenic silica microparticles as a new and sustainable cosmetic ingredient: Assessment of performance and quality parameters

The demand for sustainable products is increasing worldwide and cosmetic industry is not an exception. Besides exploring nature as source of new ingredients, their production must be sustainable and should use environmentally friendly processes. In this work, biogenic silica microparticles were synthesized from sugarcane ash, and their potential application as cosmetic and skincare ingredient was evaluated. For such application, several properties were validated, including cytotoxicity in skin keratinocytes, potential sensitization effect on skin peptides, stimulation of pro-collagen I alpha 1, wound healing capacity, as well as the ingredient stability along a storage period. Biogenic silica showed to be non-cytotoxic on skin keratinocytes, at concentrations up to 5 wt%, and non-skin sensitizer. A positive effect on the stimulation of pro-collagen I alpha 1 suggests a potential anti-ageing activity, while the migration of fibroblasts to a wounded area suggests a regenerative capacity. Under an accelerated stability study, biogenic silica showed an increase on the loss on drying, but no changes were observed on its functional properties, mainly oil absorption capacity, as well the microbiological quality, which was maintained. Overall, novel biogenic silica microparticles produced from a sustainable source are safe, stable over time and have potential to be used as a cosmetic and skincare ingredient.

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.

Bacterial collagen-templated synthesis and assembly of inorganic particles

Collagen has been used as a common template for mineralization and assembly of inorganic particles, because of the special arrangement of its fibrils and the presence of charged residues. Streptococcal bacterial collagen, which is inherently secreted on the surface ofStreptococcus pyogenes, has been progressively used as an alternative for type I animal collagen. Bacterial collagen is rich in charged amino acids, which can act as a substrate for the nucleation and growth of inorganic particles. Here, we show that bacterial collagen can be used to nucleate three different inorganic materials: hydroxyapatite crystals, silver nanoparticles, and silica nanoparticles. Collagen/mineral composites show an even distribution of inorganic particles along the collagen fibers, and the particles have a more homogenous size compared with minerals that are formed in the absence of the collagen scaffold. Furthermore, the gelation of silica occurring during mineralization represents a means to produce processable self-standing collagen composites, which is challenging to achieve with bacterial collagen alone. Overall, we highlight the advantage of simply combining bacterial collagen with minerals to expand their applications in the fields of biomaterials and tissue engineering, especially for bone regenerative scaffolds.

Gel dressing based on type I collagen modified with oligourethane and silica for skin wound healing

Cutaneous wound healing is a complex process that leads the skin reparation with the formation of scar tissue that typically lacks skin appendages. This fact drives us to find new strategies to improve regenerative healing of the skin. This study outlines, the contribution of colloidal silica particles and oligourethane crosslinking on the collagen material properties and the effect on skin wound healing in rats. We characterized the gel properties that are key forin-situgelation, which is accomplished by the latent reactivity of oligourethane bearing blocked isocyanate groups to crosslink collagen while entrapping silica particles. The swelling/degradation behavior and the elastic modulus of the composite gel were consistent with the modification of collagen type I with oligourethane and silica. On the other hand, these gels were characterized as scaffold for murine macrophages and human stem cells. The application of a composite gel dressing on cutaneous wounds showed a histological appearance of the recovered skin as intact skin; featured by the epidermis, hair follicles, sebaceous glands, subcutaneous adipose layer, and dermis. The results suggest that the collagen-based composite dressings are promising modulators in skin wound healing to achieve a regenerative skin closure with satisfactory functional and aesthetic scars.

Antibacterial and Wound-Healing Activities of Statistically Optimized Nitrofurazone- and Lidocaine-Loaded Silica Microspheres by the Box-Behnken Design

In the current study, nitrofurazone- (NFZ) and lidocaine-loaded (LD) silica microspheres were fabricated to address pathological indications of skin infections. The microspheres were prepared by the sol–gel method applying the Box–Behnken design and evaluated for size distribution, morphology, zeta potential, physico-chemical compatibility, XRD, thermogravimetric analysis, antibacterial and cytotoxicity activities. The comparative in vitro drug release study of microspheres revealed a 30% release of NFZ and 33% of LD after 8 h. The microspheres showed 81% percentage yield (PY) and 71.9% entrapment efficiency. XRD patterns confirmed the entrapment of NFZ–LD in silica microspheres with a significant reduction in crystallinity of the drugs. Thermal and FTIR studies proved the absence of any profound interactions of the formulation ingredients. The smooth spherical microspheres had a −28 mV zeta potential and a 10–100 µm size distribution. In vitro antibacterial activities of the NFZ–LD microspheres showed an increased zone of inhibition compared to pure drug suspensions. The in vivo efficacy tested on rabbits showed a comparatively rapid wound healing with complete lack of skin irritation impact. The cytotoxicity studies revealed more acceptability of silica microspheres with negligible harm to cells. The study suggests that the NFZ- and LD-loaded silica microspheres would be an ideal system for accelerating and promoting rapid healing of various acute and chronic wounds.

Synthesis And Evaluation of Polyethylene Glycol-4000-Co-Poly (AMPS) Based Hydrogel Membranes for Controlled Release of Mupirocin for Efficient Wound Healing

BACKGROUND

Chronic wound healing is a major challenge for health care system around the globe. Current study was conducted to develop and characterize chemically cross-linked polyethylene glycol-co-poly (AMPS) hydrogel membranes to enhanced the wound healing efficiency of antibiotic mupirocin (MP).

METHODS

Free radical polymerization technique was used for the development of hydrogel membranes. In aqueous medium, polymer PEG-4000 cross-linked with the monomer 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in the presence of initiators ammonium peroxide sulfate (APS) and sodium hydrogen sulfite (SHS). N, N-Methylenebisacrylamide (MBA) was used as cross-linker in the preparation of hydrogel membranes. Developed membranes were spherical, transparent, and elastic. FTIR, TGA/DSC, and SEM were used to characterize the polymeric system. Swelling behavior, drug loading, and its release pattern at pH of 5.5 and 7.4, irritation study, ex vivo drug permeation, and deposition study was also evaluated.

RESULTS

Formed membranes were spherical, transparent and elastic. The formation of a stable polymeric network was confirmed by structural and thermal analysis. Permeation of the drug its deposition in the skin showed good permeation and retention. No irritancy to the skin was observed.

CONCLUSION

On the basis of results obtained, the present study concluded that it may be an ideal network for the delivery of mupirocin in skin infections.

Mupirocin-Loaded Chitosan Microspheres Embedded in Piper betle Extract Containing Collagen Scaffold Accelerate Wound Healing Activity

This study reports the formulation of mupirocin-loaded chitosan microspheres embedded in Piper betle extract containing collagen scaffold as combinational drug delivery for improved wound healing. Selection of chitosan type (molecular weight and degree of deacetylation) was carried out based on their antibacterial efficacy. The low molecular weight chitosan was selected owing to the highest antibacterial action against gram-positive as well as gram-negative bacteria. Low molecular weight chitosan-microspheres showed spherical shape with largely smooth surface morphology, 11.81% of mupirocin loading, and its controlled release profile. The XRD, DSC thermograms, and FT-IR spectral analysis revealed the mupirocin loaded in molecularly dispersed or in amorphous form, and having no chemical interactions with the chitosan matrix, respectively. The in vivo study indicates potential effect of the mupirocin, Piper betle, and chitosan in the collagen scaffold in the wound healing efficiency with approximately 90% wound healing observed at the end of 15 days of study for combinational drug-loaded chitosan microspheres-collagen scaffold-treated group. The histopathology examination further revealed tissue lined by stratified squamous epithelium, collagen deposition, fibroblastic proliferation, and absence of inflammation indicating relatively efficient wound healing once treated with combinational drug-loaded chitosan microspheres containing scaffold.

Nanomaterials for application in wound Healing: current state-of-the-art and future perspectives

Nanoparticles are the gateway to the new era in drug delivery of biocompatible agents. Several products have emerged from nanomaterials in quest of developing practical wound healing dressings that are nonantigenic, antishear stress, and gas-exchange permeable. Numerous studies have isolated and characterised various wound healing nanomaterials and nanoproducts. The electrospinning of natural and synthetic materials produces fine products that can be mixed with other wound healing medications and herbs. Various produced nanomaterials are highly influential in wound healing experimental models and can be used commercially as well. This article reviewed the current state-of-the-art and briefly specified the future concerns regarding the different systems of nanomaterials in wound healing (i.e., inorganic nanomaterials, organic and hybrid nanomaterials, and nanofibers). This review may be a comprehensive guidance to help health care professionals identify the proper wound healing materials to avoid the usual wound complications.

Construction of a dual-responsive dual-drug delivery platform based on the hybrids of mesoporous silica, sodium hyaluronate, chitosan and oxidized sodium carboxymethyl cellulose

An intelligent drug delivery platform based on the hybrids of mesoporous silica nanoparticles (MSN), sodium hyaluronate (HA), chitosan (CS) and oxidized sodium carboxymethyl cellulose (oxCMC) is developed, which can be used for dual-responsive dual-drug delivery. Hydrophilic cytarabine (Cyt) is first loaded into the mesopores of the aminated MSN (NH₂-MSN), which is encapsulated by the hydrogel of HA and cystamine (Cys) crosslinked via amidation. The Cyt encapsulated hydrogel which is denoted as Cyt/NH₂-MSN/HA is co-encapsulated with hydrophobic methotrexate (MTX) into the hydrogel of CS and oxCMC resulted from Schiff base reaction. Since the acylhydrazone bonds (-HC=N-) between CS and oxCMC are sensitive to pH and the disulfide bonds (-S-S-) in Cys are sensitive to glutathione (GSH), the resultant dual-drug encapsulated hydrogel, denoted as Cyt/NH₂-MSN/HA/MTX/CS/oxCMC, can be used for dual-responsive (pH and GSH) drug delivery. The results of cell viability demonstrate that the developed dual-drug encapsulated hydrogel has significantly higher efficacy of chemotherapy than that of single-drug (MTX or Cyt) encapsulated hydrogel.

Locust Bean Gum: Processing, Properties and Food Applications

Locust bean gum is derived from the seed endosperm of the Ceratonia siliqua carob tree and is known as locust bean or carob gum. Food, medicines, paper, textile, oil drilling, and cosmetic sectors all use it as an ingredient. Hydrogen bonding with water molecules makes locust bean gum useful in industrial settings. In addition, its dietary fibre activity helps regulate numerous health issues, including diabetes, bowel motions, heart disease and colon cancer. Locust bean gum production, processing, composition, characteristics, culinary applications, and health advantages are the subject of this article.

Evaluation of the osteogenic potential of crocin-incorporated collagen scaffold on the bone marrow mesenchymal stem cells

OBJECTIVE

The present study aimed to evaluate the effect of crocin (CRO)-loaded collagen (COL) scaffold on the osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BM-MSCs).

SIGNIFICANCE

Different studies have been conducted to develop an efficient strategy to accelerate and improve the recovery process of bone defects. It was shown that CRO, extracted from saffron, could induce osteogenic differentiation of rat BM-MSCs. Scaffolds can also provide a three-dimensional environment for migration, adhesion, growth, and proliferation of MSCs.

METHODS

Collagen scaffolds were fabricated through freeze-drying followed by cross-linking by dehydrothermal method. Then, CRO was incorporated into the scaffolds. Physicochemical characterization of the scaffolds was evaluated. Rat BM-MSCs were seeded on CRO-loaded COL scaffolds and cultured for 14 days. Osteogenic differentiation was evaluated using alizarin red (ALZ) staining and alkaline phosphatase (ALP) activity assay and compared to the positive control group.

RESULTS

The average pore size of the COL scaffolds was about 97 ± 6.7 µm. Formation of amide cross-links was confirmed by FTIR. The scaffolds were capable of uptaking water up to 50 times more than their initial dry weight and releasing above 90% of their uploaded CRO during 24 h. Collagen scaffolds containing CRO (25 and 50 μM) increased ALZ intensity (3.16 ± 0.3 and 7.32 ± 0.3 folds, respectively) and ALP activity (13.7 ± 1.1 and 12.2 ± 9.4 folds, respectively) in comparison with the positive control group.

CONCLUSION

Crocin-loaded COL scaffold could effectively enhance calcium deposition and ALP activity in BM-MSCs and therefore proposed as a good candidate to accelerate the healing process of vital bone defects.

Long term storage of miRNA at room and elevated temperatures in a silica sol-gel matrix

Storage of biospecimens in their near native environment at room temperature can have a transformative global impact, however, this remains an arduous challenge to date due to the rapid degradation of biospecimens over time. Currently, most isolated biospecimens are refrigerated for short-term storage and frozen (-20 °C, -80 °C, liquid nitrogen) for long-term storage. Recent advances in room temperature storage of purified biomolecules utilize anhydrobiosis. However, a near aqueous storage solution that can preserve the biospecimen nearly "as is" has not yet been achieved by any current technology. Here, we demonstrate an aqueous silica sol-gel matrix for optimized storage of biospecimens. Our technique is facile, reproducible, and has previously demonstrated stabilization of DNA and proteins, within a few minutes using a standard benchtop microwave. Herein, we demonstrate complete integrity of miRNA 21, a highly sensitive molecule at 4, 25, and 40 °C over a period of ∼3 months. In contrast, the control samples completely degrade in less than 1 week. We attribute excellent stability to entrapment of miRNA within silica-gel matrices.

Effectiveness of Green Synthesis of Silver/Kaolinite Nanocomposite Using Quercus infectoria Galls Aqueous Extract and Its Chitosan-Capped Derivative on the Healing of Infected Wound

Kaolinite nanocomposites (NCs) could be utilized as agents for wound healing owing to their efficiency and low toxicity. The present study was conducted to synthesize a novel silver/kaolinite NCs (Ag/Kaol NCs) and investigate their chitosan derivation (Ag/Kaol/Chit NCs) using oak extract. XRD, SEM, EDX, FT-IR, and DLS were employed for the investigation of structural and physio-chemical properties of the synthesized NCs. The obtained results revealed that synthesized Ag/Kaol NCs were mesoporous and spherical with sizes ranging from 7-11 nm. They also demonstrated successful synthesis between silver and kaolinite using the extract. Cytotoxicity and in vitro antibacterial activity were also investigated. The clinical effects of ointments containing the NCs for improving wound healing were studied on the wound area, total bacterial count, histological parameters, and protein expression of some genes. Nanocomposites were safe up to 0.50 mg/mL. The results of in vivo and in vitro antibacterial activity showed that Ag/Kaol NCs, were of antibacterial activity ( ). The results of antioxidant activity indicated that Ag/Kaol NCs have antioxidant structures. Our findings concerning molecular mechanism implied that Ag/Kaol/Chit increased the expression of Wnt/ β -catenin and collagen ( ). In sum, Ag/Kaol/Chit showed antibacterial activity and improved wound healing by decreasing the inflammation and promoting the proliferative phase. The novel NCs showed wound healing properties by decreasing inflammation and total bacterial count and increasing proliferative phase. The application of Ag/Kaol/Chit was suggested as a green agent for improving infected wound healing.

Chitosan-bovine serum albumin-Carbopol 940 nanogels for mupirocin dermal delivery: ex-vivo permeation and evaluation of cellular binding capacity via radiolabeling

The goal of this study was to develop and examine the nanogel-based topical delivery system of mupirocin. Nanogels were prepared with chitosan and bovine serum albumin by ionic gelation and Carbopol 940 was added to improve the gelling/adhesive properties. Detailed characterization studies were performed and the cellular binding capacity of radiolabeled nanogels was investigated on CCD-1070Sk cell lines. Results indicate the successful formation of nanogels with particle size and zeta potential ranged between 341.920-603.320 nm and 13.120-24.300 mV, respectively. The mechanical and rheological studies proved pseudoplastic and strong elastic gel behavior (G' > G''). Mupirocin was successfully entrapped into nanogels with a ratio of more than 95% and the loaded drug was slowly released up to 93.89 ± 3.07% within 24 h. The ex vivo penetration and permeation percentages of mupirocin were very low (1.172 ± 0.202% and 0.161 ± 0.136%) indicating the suitability of nanogels for dermal use against superficial skin infections. The microbiological studies pointed out the effectiveness of nanogels against Staphylococcus aureus strains. Nanogels did not show toxicity signs and the cell binding capacity of radiolabeled formulations was found to be higher than [^99mTc]NaTcO₄ to CCD-1070Sk cell line. Overall, mupirocin nanogels might be considered as a potential and safe topical treatment option for bacterial skin infections.

Pharmaco-Technical Evaluation of Statistically Formulated and Optimized Dual Drug-Loaded Silica Nanoparticles for Improved Antifungal Efficacy and Wound Healing

The current research aimed at designing mesoporous silica nanoparticles (MSNs) for a controlled coadministration of salicylic acid (SA) and ketoconazole (KCZ) to effectively treat highly resistant fungal infections. The sol-gel method was used to formulate MSNs, which were further optimized using central composite rotatable design (CCRD) by investigating mathematical impact of independent formulation variables such as pH, stirring time, and stirring speed on dependent variables entrapment efficiency (EE) and drug release. The selected optimized MSNs and pure drugs were subjected to comparative in vitro/in vivo antifungal studies, skin irritation, cytotoxicity, and histopathological evaluations. The obtained negatively charged (-23.1), free flowing spherical, highly porous structured MSNs having a size distribution of 300-500 nm were suggestive of high storage stability and improved cell proliferation due to enhanced oxygen supply to cells. The physico-chemical evaluation of SA/KCZ-loaded MSNs performed through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) indicates absolute lack of any interaction between formulation components and successful encapsulation of both drugs in MSNs. The EE_SA, EE_KCZ, SA release, and KCZ release varied significantly from 34 to 89%, 36 to 85%, 39 to 88%, and 43 to 90%, respectively, indicating the quadratic impact of formulation variables on obtained MSNs. For MSNs, the skin tolerability and cell viability percentage rate were also having an extraordinary advantage over suspension of pure drugs. The optimized SA/KCZ-loaded MSNs demonstrated comparatively enhanced in vitro/in vivo antifungal activities and rapid wound healing efficacy in histopathological evaluation without any skin irritation impact, suggesting the MSNs potential for the simultaneous codelivery of antifungal and keratolyic agents in sustained release fashion.

Ferulic acid loaded microspheres reinforced in 3D hybrid scaffold for antimicrobial wound dressing

Here we report the preparation of biomimetic fibrin/chitosan/keratin hybrid scaffolds with a synergistic combination of ferulic acid loaded silica microspheres for antimicrobial wound dressing applications. The infrared and X-ray powder diffraction studies confirm the homogenous nature of the prepared hybrid scaffolds without any major interactions between the constituents. The developed hybrid scaffolds show good thermal, porosity, compression and water uptake properties. Scanning electron microscopic analysis shows that the as-synthesized ferulic acid loaded silica microspheres exhibit an average size of 35 ± 10 μm and also exposes the smooth surface with interconnected porosity in the prepared hybrid scaffolds. The incorporated ferulic acid loaded silica microspheres hybrid scaffolds show effective antimicrobial activity against the common wound pathogens. In vitro NIH3T3 fibroblast cell culture and drug release studies reveal that the prepared hybrid scaffolds have enhanced cell proliferation and adhesion with a prolonged drug release for about 72 h. In vitro wound healing and actin cytoskeleton analysis reveal that the incorporated ferulic acid loaded silica microspheres in fibrin/chitosan/keratin hybrid scaffolds facilitates cell growth and migration to damaged area through cell-cell interactions. These results suggest that the prepared hybrid scaffolds with ferulic acid loaded silica microspheres have great potential for soft tissue engineering applications particularly for the treatment of chronic and infected wounds.

Fabrication of ciprofloxacin-loaded chitosan/polyethylene oxide/silica nanofibers for wound dressing application: In vitro and in vivo evaluations

Silica plays an effective role in collagen creation; hence, the degradation products of silica-based materials accelerate wound healing. In this regard, chitosan/polyethylene oxide/silica hybrid nanofibers were prepared by the combining the sol-gel method with electrospinning technique to accelerate the wound healing process. Ciprofloxacin, as an antibacterial drug, was then added to the electrospinning mixture. The nanofibers were characterized by SEM, EDX, X-ray mapping, TEM, TGA, FTIR, and XRD analysis. The degradation, swelling ratio, and release of ciprofloxacin were investigated in PBS. The prepared nanofiber could absorb water, maintain its morphological integrity during the degradation process, and gradually release ciprofloxacin. The nanofibers revealed an efficient antibacterial activity against Escherichia coli and Staphylococcus aureus. Cell viability assays showed that the nanofibers had no cytotoxicity against L929 mouse fibroblast and HFFF2 human foreskin fibroblast cell lines. The potential of the chitosan/polyethylene oxide/silica/ciprofloxacin nanofiber for healing full-thickness wound was assessed by applying the scaffold in the dorsal cutaneous wounds of the Balb/C mice. The white blood cell counts of the animals indicated the nanofiber-treated mice compared with the untreated ones had less infection and inflammation. According to the histopathologic data, the prepared nanofiber accelerated and enhanced tissue regeneration by increasing fibroblast cells and angiogenesis as well as decreasing the inflammation phase. The findings suggest that the prepared antibacterial scaffold with drug delivery properties could be an appropriate candidate for many medical and hygienic applications, especially as a bio-compatible and bio-degradable wound dressing.

Polycaprolactone nanofiber coated with chitosan and Gamma oryzanol functionalized as a novel wound dressing for healing infected wounds

This study was conducted to design and evaluate a wound dressing based on a polycaprolactone (PCL) nanofiber coated with gamma oryzanol (GO) and chitosan (CS) in mice model. All the dressings were prepared by electrospinning method, and their morphology and physical properties were investigated. The mice were divided into five groups and treated with I) PCL-sole (PCL), III) PCL-mupirocin (PCL-M), IV) PCL-GO, IV) PCL-CS, and V) PCL-CS-GO. Wound area, total bacterial count, histopathological parameters, and expressions of IL-1β, TNF-α, IL-10, MMP-9, EGF, and VEGF were assessed. The fibers were randomly distributed in PCL group, but loading CS and GO increased the complexity and placing on the dressings. PCLs loaded with GO and CS showed lower viscosity, surface tension, and fiber diameter and higher conductivity and water contact angle compared to unloaded PCLs (P < 0.05). The treatment with PCLs loaded with mupirocin, CS, and GO significantly reduced wound area and total bacterial count (P < 0.05). Loading PCLs with mupirocin, CS, and GO decreased the expressions of IL-1β, TNF-α, MMP-9, but increased the expressions of IL-10 and VEGF compared to the unloaded PCL group (P < 0.05). The most optimal responses to wound healing and physical parameters belonged to the PCL-CS-GO group.

Drug delivery to optimize angiogenesis imbalance in keloid: A review

The wound healing process involves three continuous stages. Where, any imbalance can lead to the formation of unwanted keloids, hypertrophic scar, or tumors. Keloids are any unpleasant, non-compliant comorbidity affecting a major section of people around the globe who acquire it either genetically or by pathological means as a result of a skin injury. Angiogenesis is unavoidable in the healing process after an injury or disruption of skin to promote tissue regeneration. Uncontrolled angiogenesis during the healing process can initiate the unwanted response in the wound that facilitate keloid. Angiogenic therapy is adapted to accelerate healing after an injury. Else ways, there exists a risk of keloid formation due to excessive angiogenesis during the wound healing process. There are numerous strategies to treat keloid. Anti-angiogenic factors are provided to patients post-surgery to prevent the keloid formation; however, they come into the picture after the formation of keloid. The available strategies to treat keloids are steroidal injections, surgical excision of the keloid, radiotherapy, pressure therapy, the use of cryosurgery, and many more. The available treatments are not promising in reducing the recurrent rate of keloids as there are chances of high re-occurrences with similar/larger lesions on the removed keloid site. In this review, we are discussing the importance of controlled angiogenesis with the help of controlled drug delivery strategies enabling the wound healing process without the induction of keloid.

Multifunctional Chitosan/Polycaprolactone Nanofiber Scaffolds with Varied Dual-Drug Release for Wound-Healing Applications

Electrospinning-based wound dressings with multifunctional properties, including hemostasis-promoting, antibacterial, drug release, and therapeutic effects, are of great interest in military and civilian trauma healthcare. Herein, we designed lidocaine hydrochloride (LID) and mupirocin-loaded chitosan/polycaprolactone (CSLD-PCLM) scaffolds with multiple functions as wound dressings. Through the dual spinneret electrospinning technique, the scaffolds achieved a nanofiber structure, which enhanced the interfacial interaction between the scaffold and blood cells and showed excellent blood coagulation capacity. In particular, the scaffolds loaded with LID and mupirocin exhibited rapid release of LID and sustained release of mupirocin. The CSLD-PCLM scaffold containing mupirocin exhibited outstanding antibacterial activity. Moreover, the scaffold significantly enhanced the wound healing process with complete re-epithelialization as well as collagen deposition in a full-thickness skin defect model. Thus, CSLD-PCLM nanofibrous scaffolds may ideally meet the various requirements of the wound healing process and are promising candidates for wound dressings in future clinical applications.

Understanding the mechanisms of silica nanoparticles for nanomedicine

As a consequence of recent progression in biomedicine and nanotechnology, nanomedicine has emerged rapidly as a new discipline with extensive application of nanomaterials in biology, medicine, and pharmacology. Among the various nanomaterials, silica nanoparticles (SNPs) are particularly promising in nanomedicine applications due to their large specific surface area, adjustable pore size, facile surface modification, and excellent biocompatibility. This paper reviews the synthesis of SNPs and their recent usage in drug delivery, biomedical imaging, photodynamic and photothermal therapy, and other applications. In addition, the possible adverse effects of SNPs in nanomedicine applications are reviewed from reported in vitro and in vivo studies. Finally, the potential opportunities and challenges for the future use of SNPs are discussed.

This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Ferulic acid-loaded collagen hydrolysate and polycaprolactone nanofibres for tissue engineering applications

There is a great need for the progress of composite biomaterials, which are effective for tissue engineering applications. In this work, the development of composite electrospun nanofibres based on polycaprolactone (PCL) and collagen hydrolysate (CH) loaded with ferulic acid (FA) for the treatment of chronic wounds. Response Surface Methodology (RSM) has been applied to nanofibres factor manufacturing assisted by electrospinning. For wound healing applications, the authors have created the efficacy of CH, and PCL membranes can act as a stable, protective cover for wound, enabling continuous FA release. The findings of the RSM showed a reasonably good fit with a polynomial equation of the second order which was statistically acceptable at P < 0.05. The optimised parameters include the quantity of hydrolysate collagen, the voltage applied and the distance from tip-to-collector. Based on the Box-Behnken design, the RSM was used to create a mathematical model and optimise nanofibres with minimum diameter production conditions. Using FTIR, TGA and SEM, optimised nanofibres were defined. In vitro, cytocompatibility trials showed that there was an important cytocompatibility of the optimised nanofibres, which was proved by cell proliferation and cell morphology. In this research, the mixed nanofibres of PCL and CH with ferulic could be a potential biomaterial for wound healing.

Development of a polyvinyl alcohol/sodium alginate hydrogel-based scaffold incorporating bFGF-encapsulated microspheres for accelerated wound healing

In the present study, a hybrid microsphere/hydrogel system, consisting of polyvinyl alcohol (PVA)/sodium alginate (SA) hydrogel incorporating PCL microspheres is introduced as a skin scaffold to accelerate wound healing. The hydrogel substrate was developed using the freeze-thawing method, and the proportion of the involved polymers in its structure was optimized based on the in-vitro assessments. The bFGF-encapsulated PCL microspheres were also fabricated utilizing the double-emulsion solvent evaporation technique. The achieved freeze-dried hybrid system was then characterized by in-vitro and in-vivo experiments. The results obtained from the optimization of the hydrogel showed that increasing the concentration of SA resulted in a more porous structure, and higher swelling ability, elasticity and degradation rate, but decreased the maximum strength and elongation at break. The embedding of PCL microspheres into the optimized hydrogel structure provided sustained and burst-free release kinetics of bFGF. Besides, the addition of drug-loaded microspheres led to no significant change in the degradation mechanism of the hydrogel substrate; however, it reduced its mechanical strength. Furthermore, the MTT assay represented no cytotoxic effect for the hybrid system. The in-vivo studies on a burn-wound rat model, including the evaluation of the wound closure mechanism, and histological analyses indicated that the fabricated scaffold efficiently contributed to promoting cell-induced tissue regeneration and burn-wound healing.

Poly(hydroxybutyrate-co-hydroxyvalerate) microparticles embedded in κ-carrageenan/locust bean gum hydrogel as a dual drug delivery carrier

A novel composite hydrogel was prepared as a dual drug delivery carrier. Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microparticles were prepared to encapsulate simultaneously ketoprofen and mupirocin, as hydrophobic drug models. These microparticles were embedded in a physically crosslinked hydrogel of κ-carrageenan/locust bean gum. This composite hydrogel showed for both drugs a slower release than the obtained release from microparticles and hydrogel separately. The release of both drugs was observed during a period of 7 days at 37 °C. Different kinetic models were analyzed and the results indicated the best fitting to a Higuchi model suggesting that the release was mostly controlled by diffusion. Also, the drug loaded microparticles were spherical with average mean particle size of 1.0 μm, mesoporous, and distributed homogeneously in the hydrogel. The composite hydrogel showed a thermosensitive swelling behavior reaching 183% of swelling ratio at 37 °C. The composite hydrogel showed the elastic component to be higher than the viscous component, indicating characteristics of a strong hydrogel. The biocompatibility was evaluated with in vitro cytotoxicity assays and the results indicated that this composite hydrogel could be considered as a potential biomaterial for dual drug delivery, mainly for wound healing applications.

Nano-drug delivery systems in wound treatment and skin regeneration

Skin damages are defined as one of most common lesions people suffer from, some of wounds are notoriously difficult to eradicate such as chronic wounds and deep burns. Existing wound therapies have been proved to be inadequate and far from satisfactory. The cutting-edge nanotechnology offers an unprecedented opportunity to revolutionize and invent new therapies or boost the effectiveness of current medical treatments. In particular, the nano-drug delivery systems anchor bioactive molecules to applied area, sustain the drug release and explicitly enhance the therapeutic efficacies of drugs, thus making a fine figure in field relevant to skin regeneration. This review summarized and discussed the current nano-drug delivery systems holding pivotal potential for wound healing and skin regeneration, with a special emphasis on liposomes, polymeric nanoparticles, inorganic nanoparticles, lipid nanoparticles, nanofibrous structures and nanohydrogel.

An alternative approach to wound healing field; new composite films from natural polymers for mupirocin dermal delivery

In this study, novel adhesive films were prepared for Mupirocin dermal delivery. Natural polymers as chitosan, sodium alginate and carbopol were used for films development to evaluate possible interactions and drug release properties. Solvent evaporation method was used for films preparation. Preliminary studies involved FT-IR spectroscopy and Scanning Electron Microscopy to specify interactions and morphology. Thickness, tensile strength and water uptake in phosphate buffer saline were evaluated whereas in vitro release studies were also performed. In vitro drug release studies demonstrated that mupirocin release was improved. Ex vivo bioadhesion and permeation studies using Balb-c mice were performed to check the suitability of the films. Antimicrobial ability was evaluated by agar well diffusion tests. Finally, excisional wound model applied to test the wound healing effect and evaluated macroscopic and histopathologically. One formulation was found more effective compared to the market product for wound healing at Balb-c mice.

A Facile Approach to Fabricate Dual Purpose Hybrid Materials for Tissue Engineering and Water Remediation

Creating hybrid materials with multifunctionality and robust mechanical stability from natural resources is a challenging proposition in materials science. Here, we report the scalable synthesis of hybrid collagen scaffolds using collagen extracted from leather industry wastes and sago starch derived from agro-industry. The hybrid scaffolds were incorporated with TiO2 nanoparticles and cross-linked with oxidized sago starch. The biocompatibility, thermal stability and antimicrobial property of hybrid scaffold enabled its application in burn wound healing demonstrated through albino rat models. The highly porous hybrid scaffolds are shown to be super-compressible, which is typically forbidden in materials of biological origin. We demonstrate that the hybrid scaffolds concurrently display both adsorption and absorption behavior in the removal of oil and dye molecules, respectively from contaminated water. This study paves the way for the development of novel multifunctional and shape recoverable hybrid materials specifically from renewable resources.

Recent advances in inorganic nanomaterials for wound-healing applications

The emergence of inorganic nanoparticles has generated considerable expectation for solving various biomedical issues including wound healing and tissue regeneration. This review article highlights the role and recent advancements of inorganic nanoparticles for wound healing and tissue regeneration along with their advantages, clinical status, challenges and future directions.

Type I collagen peptides and nitric oxide releasing electrospun silk fibroin scaffold: A multifunctional approach for the treatment of ischemic chronic wounds

Biomimetic nanofibrous scaffolds targeting multiple dysfunctional processes provide a multi-pronged strategy to restore functions and regenerate the damaged tissue. This study investigates a strategy of combining a regenerative component, Type I collagen Peptide (CP), along with a nitric oxide donor, S-Nitrosoglutathione (GSNO), in the form of nanofibrous scaffold to address the non-healing diabetic ulcer. Silk Fibroin-Polyvinyl alcohol (SF-PVA) nanofibrous scaffold is used as a carrier for delivering functional moieties. The developed nanofibrous electrospun mats (SF-PVA, CP-SF-PVA, and CP-GSNO-SF-PVA) showed continuous, bead-less and randomly oriented fibers with highly porous morphology. The in vitro biocompatibility was assessed by MTT assay, DAPI-Rhodamine 123 and FITC-Phalloidin imaging studies. CP-GSNO-SF-PVA nanofibrous scaffold showed a high degree of cell attachment, spreading of F-actin with viable cell morphology and appreciable inter-cellular connection. Thus the study showed that the proliferation of fibroblast cells are mainly facilitated by the presence of collagen peptide in the nanofibrous matrix. Griess assay demonstrated immediate release of NO for a day from the developed multifunctional scaffold. These results demonstrate the in vitro efficacy of CP-GSNO and indicate the opportunity of CP-GSNO-SF-PVA nanofibrous scaffold for the treatment of ischemic non-healing ulcers.

Synthesis and evaluation of topical hydrogel membranes; a novel approach to treat skin disorders

The aim of the study was to synthesize and evaluate chitosan-based topical cross-linked hydrogel membranes of mupirocin for new pharmaceutical controlled release application. These cross-linked structured membranes were synthesized by modification of free radical polymerization. Low molecular weight (LMW) chitosan is cross-linked with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) with a crosslinker N,N-methylenebisacrylamide (MBA). Hydrogel membranes were characterized by FTIR, DSC, TGA, SEM, Swelling behavior, sol-gel analysis, in vitro percent drug release at different pH, permeation across skin, ex vivo drug deposition study, irritation study and in vivo antibacterial activity of mupirocin loaded hydrogels. Developed membranes were spherical, adhesive and have good elastic strength. FTIR confirmed the cross-linking and formation of new structure having appropriate characteristics needed for controlled release delivery system. Drug release through rabbit's skin was evaluated by Franz diffusion cell and up to 6329.61 µg/1.5 cm² was permeated and drug deposition in skin revealed significant retention up to 1224 µg/1.5 cm². Formulated membranes were nonirritant to the skin as validated by Draize patch test. In surgical wound model, LMW chitosan-based hydrogel membranes showed prolong efficacy against bacterial infection caused by S. aureus. Enhanced retention of drug in skin demonstrated the good potential of topical delivery for skin bacterial infection.

Biopolymer nanofibrils: structure, modeling, preparation, and applications

Biopolymer nanofibrils exhibit exceptional mechanical properties with a unique combination of strength and toughness, while also presenting biological functions that interact with the surrounding environment. These features of biopolymer nanofibrils profit from their hierarchical structures that spun angstrom to hundreds of nanometer scales. To maintain these unique structural features and to directly utilize these natural supramolecular assemblies, a variety of new methods have been developed to produce biopolymer nanofibrils. In particular, cellulose nanofibrils (CNFs), chitin nanofibrils (ChNFs), silk nanofibrils (SNFs) and collagen nanofibrils (CoNFs), as the four most abundant biopolymer nanofibrils on earth, have been the focus of research in recent years due to their renewable features, wide availability, low-cost, biocompatibility, and biodegradability. A series of top-down and bottom-up strategies have been accessed to exfoliate and regenerate these nanofibrils for versatile advanced applications. In this review, we first summarize the structures of biopolymer nanofibrils in nature and outline their related computational models with the aim of disclosing fundamental structure-property relationships in biological materials. Then, we discuss the underlying methods used for the preparation of CNFs, ChNFs, SNF and CoNFs, and discuss emerging applications for these biopolymer nanofibrils.

Preparation and Evaluation of Skin Wound Healing Chitosan-Based Hydrogel Membranes

The purpose of the study was to synthesize and characterize a new form of topical membranes as chitosan-based hydrogel membranes for bacterial skin infections. The polymeric membranes were synthesized by modification in free radical solution polymerization technique. High molecular weight (HMW) chitosan polymer was cross-linked with monomer 2-acrylamido-2-methylpropane sulfonic acid (AMPS) through cross-linker N,N-methylenebisacrylamide (MBA). Mupirocin, an antibiotic, was used as model drug. The polymeric membranes were prepared in spherical form that found stable and elastic. Characterization of hydrogel membranes was performed by FTIR, SEM, DSC, TGA, swelling behavior, drug release, irritation study, and ex vivo drug permeation and deposition study. Structural and thermal studies confirmed the formation of new polymeric network with enhanced stability of hydrogel membranes. Permeation flux of drug from optimized formulation through rabbit's skin assessed by using Franz cell was up to 104.09 μg cm^-2 h^-1. Furthermore, hydrogel membrane has significant retention of drug in skin up to 2185 μg 1.5 cm^-2. Draize patch test confirmed the synthesized hydrogels as non-irritant to skin. The preparation of a topical membrane with improved antibacterial activity within controlled release manner is desirable for the advancement and treatment of skin diseases.

Electrospun PCL/mupirocin and chitosan/lidocaine hydrochloride multifunctional double layer nanofibrous scaffolds for wound dressing applications

Background

An ideal wound dressing should exhibit good biocompatibility, minimize pain and infection, absorb excess exudates, and maintain a moist environment. However, few clinical products meet all these needs. Therefore, the aim of this study was to fabricate a multifunctional double layer nanofibrous scaffolds (DLS) as a potential material for wound dressing.

Materials and methods

The scaffold was formed from mupirocin and lidocaine hydrochloride homogeneously incorporated into polycaprolactone as the first layer of scaffolds and chitosan as the second layer of scaffolds nanofibers through electrospinning. The fabricated nanofibrous scaffolds were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and measurement of swelling ratio, contact angle, drug release, and mechanical properties. Furthermore, antibacterial assessment, live/dead cell assays, and MTT assays were used to investigate the antibacterial activity and cytotoxicity of the nanofibrous scaffolds.

Results

The morphology of the nanofibrous scaffolds was studied by scanning electron microscopy, showing successful nanofibrous scaffolds. Fourier transform infrared spectroscopy demonstrated the successful incorporation of the material used to produce the produced nanofibrous scaffolds. Thermal studies with thermogravimetric analysis and differential scanning calorimetry indicated that the DLS had high thermal stability. The DLS also showed good in vitro characteristics in terms of improved swelling ratio and contact angle. The mechanical results revealed that the DLS had an improved tensile strength of 3.88 MPa compared with the second layer of scaffold (2.81 MPa). The release of drugs from the scaffold showed different profiles for the two drugs. Lidocaine hydrochlo ride exhibited an initial burst release (66% release within an hour); however, mupirocin exhibited only a 5% release. Furthermore, the DLS nanofibers displayed highly effective antibacterial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa and were nontoxic to fibroblasts.

Conclusion

The fabricated DLS exhibited excellent hydrophilicity, cytocompatibility, sustained drug release, and antibacterial activity, which are favorable qualities for its use as a multifunctional material for wound dressing applications.

Microparticles to enhance delivery of drugs and growth factors into wound sites

Microparticles with controlled size and morphology are of significant interest in the field of drug delivery. Although advanced nanoparticles have been the object of a substantial number of reviews, fewer have focused on microparticles, especially for the delivery of drugs and growth factors to the wound site. Microparticles show distinct advantages, including ease of production and characterization, extended release properties, high drug loading and little concern about the toxicity as compared with the nanosized systems. This review presents an introduction to the pathophysiology of wound healing and provides an overview of some of the recent advances in microparticle-based drugs and growth factors delivery to wound sites.

Development, Optimization and In Vitro/In Vivo Characterization of Collagen-Dextran Spongious Wound Dressings Loaded with Flufenamic Acid

The aim of this study was the development and optimization of some topical collagen-dextran sponges with flufenamic acid, designed to be potential dressings for burn wounds healing. The sponges were obtained by lyophilization of hydrogels based on type I fibrillar collagen gel extracted from calf hide, dextran and flufenamic acid, crosslinked and un-crosslinked, and designed according to a 3-factor, 3-level Box-Behnken experimental design. The sponges showed good fluid uptake ability quantified by a high swelling ratio. The flufenamic acid release profiles from sponges presented two stages—burst effect resulting in a rapid inflammation reduction, and gradual delivery ensuring the anti-inflammatory effect over a longer burn healing period. The resistance to enzymatic degradation was monitored through a weight loss parameter. The optimization of the sponge formulations was performed based on an experimental design technique combined with response surface methodology, followed by the Taguchi approach to select those formulations that are the least affected by the noise factors. The treatment of experimentally induced burns on animals with selected sponges accelerated the wound healing process and promoted a faster regeneration of the affected epithelial tissues compared to the control group. The results generated by the complex sponge characterization indicate that these formulations could be successfully used for burn dressing applications.

The Influence of Lyophilized EmuGel Silica Microspheres on the Physicomechanical Properties, In Vitro Bioactivity and Biodegradation of a Novel Ciprofloxacin-Loaded PCL/PAA Scaffold

A new composite poly(caprolactone) (PCL) and poly(acrylic acid) (PAA) (PCL:PAA 1:5) scaffold was synthesized via dispersion of PCL particles into a PAA network. Silica microspheres (Si) (2⁻12 μm) were then prepared by a lyophilized micro-emulsion/sol-gel (Emugel) system using varying weight ratios. The model drug ciprofloxacin (CFX) was used for in situ incorporation into the scaffold. The physicochemical and thermal integrity, morphology and porosity of the system was analyzed by X-Ray Diffraction (XRD), Attenuated Total Refelctance Fourier Transform Infrared (ATR-FTIR), Differential Scanning Calorimetry (DSC), SEM, surface area analysis and liquid displacement, respectively. The mechanical properties of the scaffold were measured by textural analysis and in vitro bioactivity, biodegradation and pH variations were evaluated by XRD, FTIR and SEM after immersion in Simulated Body Fluid (SBF). The in vitro and in vivo studies of the prepared scaffold were considered as future aspects for this study. CFX release was determined in phosphate buffer saline (PBS) (pH 7.4; 37 °C). The incorporation of the Si microspheres and CFX into the scaffold was confirmed by XRD, FTIR, DSC and SEM, and the scaffold microstructure was dependent on the concentration of Si microspheres and the presence of CFX. The system displayed enhanced mechanical properties (4.5⁻14.73 MPa), in vitro bioactivity, biodegradation and controlled CFX release. Therefore, the PCL/PAA scaffolds loaded with Si microspheres and CFX with a porosity of up to 87% may be promising for bone tissue engineering.