Local delivery of resveratrol using polycaprolactone nanofibers for treatment of periodontal disease

Electrospun nanofibers: building blocks for the repair of bone tissue

Bone, one of the hardest structures of the body, is the basic constituent of the skeletal system, which gives the shape to the body, provides mechanical support for muscles and soft tissues, and provides movement. Even if there is no damage, bone remodeling is a permanent process to preserve and renew the structural, biochemical, and biomechanical integrity of bone tissue. Apart from the remodeling, bone healing is the highly complicated process of repairing deficiencies of bone tissue by the harmonious operation of osteoblasts, osteocytes, osteoclasts, and bone lining cells. Various materials can be used to both trigger the bone healing process and to provide mechanical support to damaged bone. Nanofiber scaffolds are at the forefront of these types of systems because of their extremely large surface area-to-volume ratio, small pore size, and high porosity. Nanofibers are known to be highly functional systems with the ability to mimic the structure and function of the natural bone matrix, facilitating osteogenesis for cell proliferation and bone regeneration. Electrospinning is an easy and fast method to produce non-woven structures consisting of continuous ultrafine fibers with diameters ranging from micrometers down to nanometers. The simplicity and cost-effectiveness of the electrospinning technique, its ability to use a wide variety of synthetic, natural, and mixed polymers, and the formation of highly porous and continuous fibers are the remarkable features of this method. The importance of nanofiber-based scaffolds in bone tissue regeneration is increasing because of suitable pore size, high porosity, osteoinduction, induction of bone growth with osteoconduction, adaptability to the target area, biodegradation, and appropriate mechanical properties, which are among the main parameters that are important in the design of polymeric bone grafts. The aim of this review is to cast light on the increasing use of nanofiber-based scaffolds in bone tissue regeneration and give an insight about bone regeneration, production techniques of the electrospun nanofibers, and varying formulation parameters in order to reach different drug delivery goals. This review also provides an extensive market research of electrospun nanofibers and an overview on scientific research and patents in the field.

Enhancing periodontal defences with nanofiber treatment: recent advances and future prospects

The term periodontal disease is used to define diseases characterised by inflammation and regeneration of the gums, cementum, supporting bone, and periodontal ligament. The conventional treatment involves the combination of scaling, root planning, and surgical approaches which are invasive and can pose certain challenges. Intrapocket administration of nanofibers can be used for overcoming challenges which can help in speeding up the wound repair process and can also be used to promote osteogenesis. To help make drug delivery more effective, nanofibers are an interesting solution. Nanofibers are nanosized 3D structures that can fill the pockets and have excellent mucoadhesion which prolongs their retention time on the target site. Moreover, their structure mimics the natural extracellular matrix which enables nanomaterials to sense local biological conditions and start cellular-level reprogramming to produce the necessary therapeutic efficacy. In this review, the significance of intrapocket administration of nanofibers using recent research for the management of periodontitis has been discussed in detail. Furthermore, we have discussed polymers used for the preparation of nanofibers, nanofiber production methods, and the patents associated with these developments. This comprehensive compilation of data serves as a valuable resource, consolidating recent developments in nanofiber applications for periodontitis management into one accessible platform.

The Incorporated Drug Affects the Properties of Hydrophilic Nanofibers

Hydrophilic nanofibers offer promising potential for the delivery of drugs with diverse characteristics. Yet, the effects of different drugs incorporated into these nanofibers on their properties remain poorly understood. In this study, we systematically explored how model drugs, namely ibuprofen, carvedilol, paracetamol, and metformin (hydrochloride), affect hydrophilic nanofibers composed of polyethylene oxide and poloxamer 188 in a 1:1 weight ratio. Our findings reveal that the drug affects the conductivity and viscosity of the polymer solution for electrospinning, leading to distinct changes in the morphology of electrospun products. Specifically, drugs with low solubility in ethanol, the chosen solvent for polymer solution preparation, led to the formation of continuous nanofibers with uniform diameters. Additionally, the lower solubility of metformin in ethanol resulted in particle appearance on the nanofiber surface. Furthermore, the incorporation of more hydrophilic drugs increased the surface hydrophilicity of nanofiber mats. However, variations in the physicochemical properties of the drugs did not affect the drug loading and drug entrapment efficiency. Our research also shows that drug properties do not notably affect the immediate release of drugs from nanofibers, highlighting the dominant role of the hydrophilic polymers used. This study emphasizes the importance of considering specific drug properties, such as solubility, hydrophilicity, and compatibility with the solvent used for electrospinning, when designing hydrophilic nanofibers for drug delivery. Such considerations are crucial for optimizing the properties of the drug delivery system, which is essential for achieving therapeutic efficacy and safety.

The Antioxidant Potential of Resveratrol from Red Vine Leaves Delivered in an Electrospun Nanofiber System

Despite the wide pharmacological action of polyphenols, their usefulness is limited due to their low oral bioavailability, which is due to their low solubility and rapid first-pass metabolism. Red vine leaf extract is an herbal medicine containing several polyphenols, with resveratrol and polydatin as the main compounds exhibiting antioxidant and anti-inflammatory properties. In the first stage of the work, using the Design of Experiment (DoE) approach, the red vine leaf extract (50% methanol, temperature 70 °C, and three cycles per 60 min) was obtained, which showed optimal antioxidant and anti-inflammatory properties. In order to circumvent the above-described limitations and use innovative technology, electrospun nanofibers containing the red vine leaf extract, polyvinylpyrrolidone (PVP), and hydroxypropyl-β-cyclodextrin (HPβCD) were first developed. The optimization of the process involved the time of system mixing prior to electrospinning, the mixture flow rate, and the rotation speed of the collector. Dissolution studies of nanofibers showed improved resveratrol release from the nanofibers (over five-fold). Additionally, a PAMPA-GIT assay confirmed significantly better buccal penetration of resveratrol from this nanofiber combination (over ten-fold). The proposed strategy for electrospun nanofibers with the red vine leaf extract is an innovative approach to better use the synergy of the biological action of active compounds present in extracts that are beneficial for the development of nutraceuticals.

Mechanochemical Properties of Mucoadhesive Tablets Based on PVP/HPβCD Electrospun Nanofibers as Local Delivery of Polygoni cuspidati Extract for Treating Oral Infections

This study investigated the ability of PVP/HPβCD-based electrospun nanofibers to enhance the dissolution rate of poorly soluble polydatin and resveratrol, the main active components of Polygoni cuspidati extract. To make a solid unit dosage form that would be easier to administer, extract-loaded nanofibers were ground. SEM examination was used to analyze the nanostructure of the fibers, and the results of the cross-section of the tablets showed that they had maintained their fibrous structure. The release of the active compounds (polydatin and resveratrol) in the mucoadhesive tablets was complete and prolonged in time. Additionally, the possibility of staying on the mucosa for a prolonged time has also been proven for both tablets from PVP/HPβCD-based nanofibers and powder. The appropriate physicochemical properties of the tablets, along with the proven antioxidant, anti-inflammatory, and antibacterial properties of P. cuspidati extract, highlight the particular benefits of the mucoadhesive formulation for use as a drug delivery system for periodontal diseases.

Advent of phytobiologics and nano-interventions for bone remodeling: a comprehensive review

Bone metabolism constitutes the intricate processes of matrix deposition, mineralization, and resorption. Any imbalance in these processes leads to traumatic bone injuries and serious disease conditions. Therefore, bone remodeling plays a crucial role during the regeneration process maintaining the balance between osteoblastogenesis and osteoclastogenesis. Currently, numerous phytobiologics are emerging as the new therapeutics for the treatment of bone-related complications overcoming the synthetic drug-based side effects. They can either target osteoblasts, osteoclasts, or both through different mechanistic pathways for maintaining the bone remodeling process. Although phytobiologics have been widely used since tradition for the treatment of bone fractures recently, the research is accentuated toward the development of osteogenic phytobioactives, constituent-based drug designing models, and efficacious delivery of the phytobioactives. To achieve this, different plant extracts and successful isolation of their phytoconstituents are critical for osteogenic research. Hence, this review emphasizes the phytobioactives based research specifically enlisting the plants and their constituents used so far as bone therapeutics, their respective isolation procedures, and nanotechnological interventions in bone research. Also, the review enlists the vast array of folklore plants and the newly emerging nano-delivery systems in treating bone injuries as the future scope of research in the phytomedicinal orthopedic applications.

Is It Possible to Improve the Bioavailability of Resveratrol and Polydatin Derived from Polygoni cuspidati Radix as a Result of Preparing Electrospun Nanofibers Based on Polyvinylpyrrolidone/Cyclodextrin?

The low bioavailability of resveratrol and polydatin obtained from Polygoni cuspidati extract limits the application of their pro-health properties. While nanofibers have attracted increasing attention in nutrition delivery due to their special properties, including an increase in the dissolution and permeability, which affects the bioavailability. Therefore, it is justified to obtain nanofibers from Polygoni cuspidati extract, which showed antioxidant and anti-inflammatory properties as a result of a presence of stilbene analogs in the Polygoni cuspidati extract (especially resveratrol and polydatin). In the first stage of the work, using the Design of Experiment (DoE) approach, the Polygoni cuspidati extract (70% of methanol, temperature 70 °C and 4 cycles) was obtained, which showed the best antioxidant and anti-inflammatory properties. Using the Polygoni cuspidati extract as a substrate, nanofibers were obtained by electrospinning. The identification of nanofibers was confirmed on the basis of the analysis of changes in XRPD diffractograms, SEM picture and FTIR-ATR spectra. Obtaining nanofibers from the Polygoni cuspidati extract significantly improved the solubility of resveratrol and polydatin (approx. 6-fold comparing to pure substance). As a consequence, the penetration coefficients of both tested resveratrol and polydatin also increased. The proposed strategy for the preparation of nanofibers from the Polygoni cuspidati extract is an innovative approach to better use the synergy of biological action of active compounds present in extracts. It is especially during the development of nutraceuticals based on the use of selected stilbenes.

Future Drug Targets in Periodontal Personalised Medicine-A Narrative Review

Periodontal disease is an infection-driven inflammatory disease characterized by the destruction of tooth-supporting tissues. The establishment of chronic inflammation will result in progressive destruction of bone and soft tissue changes. Severe periodontitis can lead to tooth loss. The disease has complex pathogenesis with an interplay between genetic, environmental, and host factors and pathogens. Effective management consists of plaque control and non-surgical interventions, along with adjuvant strategies to control inflammation and disrupt the pathogenic subgingival biofilms. Recent studies have examined novel approaches for managing periodontal diseases such as modulating microbial signaling mechanisms, tissue engineering, and molecular targeting of host inflammatory substances. Mounting evidence suggests the need to integrate omics-based approaches with traditional therapy to address the disease. This article discusses the various evolving and future drug targets, including proteomics, gene therapeutics, vaccines, and nanotechnology in personalized periodontal medicine for the effective management of periodontal diseases.

Effects of drug concentration and PLGA addition on the properties of electrospun ampicillin trihydrate-loaded PLA nanofibers

The aim of this study was to produce ampicillin trihydrate-loaded poly(lactic acid) (PLA) and PLA/poly(lactic-co-glycolic acid) (PLA/PLGA) polymeric nanofibers via electrospinning using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent for local application in tissue engineering. The effects of ampicillin trihydrate concentration (4-12%) and addition of PLGA (20-80%) on the spinnability of the solutions, morphology, average nanofiber diameter, encapsulation efficiency, drug release, and mechanical properties of PLA and PLA/PLGA nanofibers were examined. All nanofibers were bead-free and uniform. They had favorable encapsulation efficiency (approx. 90%) and mechanical properties. The increase in the amount of ampicillin trihydrate caused an increase in the diameter and burst effect of the nanofibers. The drug release ended on the 7th and 3rd day with nanofibers containing 4% and 12% of drug, respectively. The prolonged and controlled drug release for ten days was obtained with nanofibers containing 8% of drug. Thus, the ideal drug concentration was determined to be 8%. Nanofibers containing PLA/PLGA had a larger diameter than those including PLA. In addition, both the strength and elongation of nanofibers decreased depending on the increase in nanofiber size with the addition of PLGA, increased amount of drug, and ratios of PLGA. Drug release studies showed that PLA/PLGA nanofibers exhibited a lower burst effect and a decrease in drug release when compared to PLA nanofibers. Finally, PLA/PLGA nanofibers can be produced with enhanced encapsulation efficiency and mechanical properties, resulting in controlled and tailored release of ampicillin trihydrate for at least ten days. In conclusion, it was demonstrated that the addition of PLGA in different ratios and the amount of drug can be manipulated to obtain the desired properties (average nanofiber diameter, morphology, in vitro drug release, and mechanical properties) of PLA nanofibers.

Nature-Derived and Synthetic Additives to poly(ɛ-Caprolactone) Nanofibrous Systems for Biomedicine; an Updated Overview

As a low cost, biocompatible, and bioresorbable synthetic polymer, poly (ɛ-caprolactone) (PCL) is widely used for different biomedical applications including drug delivery, wound dressing, and tissue engineering. An extensive range of in vitro and in vivo tests has proven the favourable applicability of PCL in biomedicine, bringing about the FDA approval for a plethora of PCL made medical or drug delivery systems. This popular polymer, widely researched since the 1970s, can be readily processed through various techniques such as 3D printing and electrospinning to create biomimetic and customized medical products. However, low mechanical strength, insufficient number of cellular recognition sites, poor bioactivity, and hydrophobicity are main shortcomings of PCL limiting its broader use for biomedical applications. To maintain and benefit from the high potential of PCL, yet addressing its physicochemical and biological challenges, blending with nature-derived (bio)polymers and incorporation of nanofillers have been extensively investigated. Here, we discuss novel additives that have been meant for enhancement of PCL nanofiber properties and thus for further extension of the PCL nanofiber application domain. The most recent researches (since 2017) have been covered and an updated overview about hybrid PCL nanofibers is presented with focus on those including nature-derived additives, e.g., polysaccharides and proteins, and synthetic additives, e.g., inorganic and carbon nanomaterials.

The efficiency of PCL/HAp electrospun nanofibers in bone regeneration: a review

Electrospinning is a method which produces various nanofiber scaffolds for different tissues was attractive for researchers. Nanofiber scaffolds could be made from several biomaterials and polymers. Quality and virtues of final scaffolds depend on used biomaterials (even about single substance, the origin is effective), additives (such as some molecules, ions, drugs, and inorganic materials), electrospinning parameter (voltage, injection speed, temperature, …), etc. In addition to its benefits, which makes it more attractive is the possibility of modifications. Common biomaterials in bone tissue engineering such as poly-caprolactone (PCL), hydroxyapatite (HAp), and their important features, electrospinning nanofibers were widely studied. Related investigations indicate the critical role of even small parameters (like the concentration of PCL or HAp) in final product properties. These changes also, cause deference in cell proliferation, adhesion, differentiation, and in vivo repair process. In this review was focussed on PCL/HAp based nanofibers and additives that researchers used for scaffold improvement. Then, reviewing properties of gained nanofibers, their effect on cell behaviour, and finally, their valency in bone tissue engineering studies (in vitro and in vivo).

Current status and future of delivery systems for prevention and treatment of infections in the oral cavity

Oral health reflects the general health, and it is fundamental to well-being and quality of life. An infection in the oral cavity can be associated with serious complications in human health. Local therapy of these infections offers many advantages over systemic drug administration, targeting directly to the diseased area while minimizing systemic side effects. Specialized drug delivery systems into the oral cavity have to be designed in such a fashion that they resist to the aqueous environment that is constantly bathed in saliva and subject to mechanical forces. Additionally, a prolonged release of drug should also be provided, which would enhance the efficacy and also decrease the repeated dosing. This review is aimed to summarize the current most relevant findings related to local drug delivery of various drug groups for prevention and treatment of infections (viral, bacterial, fungal) and infection-related manifestations in the oral cavity. Current therapeutic challenges in regard to effective local drug delivery systems will be discussed, and the recent approaches to overcome these obstacles will be reviewed. Finally, future prospects will be overviewed to promote novel strategies that can be implemented in clinical management for prevention and treatment of oral infections.

Influence of Materials Properties on Bio-Physical Features and Effectiveness of 3D-Scaffolds for Periodontal Regeneration

Periodontal diseases are multifactorial disorders, mainly due to severe infections and inflammation which affect the tissues (i.e., gum and dental bone) that support and surround the teeth. These pathologies are characterized by bleeding gums, pain, bad breath and, in more severe forms, can lead to the detachment of gum from teeth, causing their loss. To date it is estimated that severe periodontal diseases affect around 10% of the population worldwide thus making necessary the development of effective treatments able to both reduce the infections and inflammation in injured sites and improve the regeneration of damaged tissues. In this scenario, the use of 3D scaffolds can play a pivotal role by providing an effective platform for drugs, nanosystems, growth factors, stem cells, etc., improving the effectiveness of therapies and reducing their systemic side effects. The aim of this review is to describe the recent progress in periodontal regeneration, highlighting the influence of materials' properties used to realize three-dimensional (3D)-scaffolds, their bio-physical characteristics and their ability to provide a biocompatible platform able to embed nanosystems.

Multidrug-loaded electrospun micro/nanofibrous membranes: Fabrication strategies, release behaviors and applications in regenerative medicine

Electrospun micro/nanofibrous membranes (EFMs) have been widely investigated as local drug delivery systems. Multiple drugs can be simultaneously incorporated into one EFM to create synergistic effects, reduce side effects, and play their respective roles in the complex physiological processes of tissue regeneration and postoperative adhesion prevention. Due to the versatile electrospinning techniques, sustained and programmed release behaviors of multiple drugs could be achieved by modulating the structure of the EFMs and the location of the drugs. In this review, various multidrug incorporation approaches based on electrospinning are overviewed. In particular, the advantages and limitations of each drug incorporation technique, the methods to control drug release and the effect of one drug release on another are discussed. Then the applications of multidrug-loaded EFMs in regenerative medicine, including wound healing, bone regeneration, vascular tissue engineering, nerve regeneration, periodontal regeneration and adhesion prevention are comprehensively reviewed. Finally, the future perspectives and challenges in the research of multidrug-loaded EFMs are discussed.

Electrospun Nano-Fibers for Biomedical and Tissue Engineering Applications: A Comprehensive Review

Pharmaceutical nano-fibers have attracted widespread attention from researchers for reasons such as adaptability of the electro-spinning process and ease of production. As a flexible method for fabricating nano-fibers, electro-spinning is extensively used. An electro-spinning unit is composed of a pump or syringe, a high voltage current supplier, a metal plate collector and a spinneret. Optimization of the attained nano-fibers is undertaken through manipulation of the variables of the process and formulation, including concentration, viscosity, molecular mass, and physical phenomenon, as well as the environmental parameters including temperature and humidity. The nano-fibers achieved by electro-spinning can be utilized for drug loading. The mixing of two or more medicines can be performed via electro-spinning. Facilitation or inhibition of the burst release of a drug can be achieved by the use of the electro-spinning approach. This potential is anticipated to facilitate progression in applications of drug release modification and tissue engineering (TE). The present review aims to focus on electro-spinning, optimization parameters, pharmacological applications, biological characteristics, and in vivo analyses of the electro-spun nano-fibers. Furthermore, current developments and upcoming investigation directions are outlined for the advancement of electro-spun nano-fibers for TE. Moreover, the possible applications, complications and future developments of these nano-fibers are summarized in detail.

Electrospinning of linezolid loaded PLGA nanofibers: effect of solvents on its spinnability, drug delivery, mechanical properties, and antibacterial activities

Objective: The choice of a desirable solvent/solvent system is fundamental for optimization of electrospinning by altering the rheological and electrostatic properties of the polymer solutions.Methods: The effects of the solvents and their properties on the viscosity and spinnability of the polymer solutions and the diameter, morphology, in vitro drug release, drug release mechanisms, antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and mechanical properties of electrospun poly-(d,l-lactide-co-glycolide) (PLGA) nanofibers were investigated. Dichloromethane (DCM), dimethylformamide (DMF), various ratios of DCM:DMF, and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) were used as solvents.Results: Although solutions containing DCM/DMF alone were not spinnable, different ratios of DCM:DMF and HFIP were determined as suitable solvents to produce nanofibers because of high enough conductivity, viscosity, and low enough surface tension of the solutions. The DCM:DMF ratio was highly effective on viscosity, nanofiber diameter, morphology, and linezolid release rate. The viscosity of HFIP containing solution was higher and the obtained nanofibers were thicker and smoother with better mechanical properties. The release of nanofibers containing HFIP at a concentration of 10% w/v PLGA was more prolonged than nanofibers containing DCM:DMF mixture. The effect of linezolid content on nanofibers was also investigated. As the amount of linezolid increased, nanofiber diameter and drug release increased and bead formation was observed. While antibacterial activity with nanofibers for which DCM:DMF was used, lasted for 13 days, it was extended to 16 days in nanofibers for which HFIP was used.Conclusions: Type and ratio of the solvent system affected viscosity and spinnability of the solutions, the average nanofiber diameter, morphology, in vitro activity and mechanical properties of the obtained electrospun nanofibers.

In vitro and in vivo evaluation of linezolid loaded electrospun PLGA and PLGA/PCL fiber mats for prophylaxis and treatment of MRSA induced prosthetic infections

In this study, it was aimed to formulate linezolid loaded electrospun PLGA and PCL fiber mats doing controlled drug release, to be used in the treatment and prophylaxis of the prosthesis related infections. The effect of PLGA concentration, PLGA to PCL ratio and the amount of linezolid on the fiber and mat properties were examined. Fiber diameter has been shown to increase with increasing amount of PLGA and linezolid. Increase in PLGA amount resulted in reduced linezolid release, whereas increase in linezolid amount resulted in increased drug release. All PLGA fiber mats have shown to have favorable encapsulation efficiency (≥73%) and mechanical properties. Encapsulation efficiency and the mechanical properties deteriorated with the addition of PCL to the formulations. PLGA fiber mats have shown a biphasic controlled release and in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), pattern up to one month. The formulation selected as the optimum has been evaluated in vivo on the infected rats, which had prosthetic implantation after bone fracture. Consequently, it has been demonstrated microbiologically and histopathologically that a more efficient therapy and prophylaxis have been achieved with a 37-fold lower dose of linezolid.

Enhanced Stability and Bioactivity of Curcuma comosa Roxb. Extract in Electrospun Gelatin Nanofibers

Electrospun fiber can be used as a carrier for releasing active ingredients at the target site to achieve the effects of drug treatment. The objectives of this research work were to study suitable conditions for producing electrospun gelatin fiber loaded with crude Curcuma comosa Roxb. extract (CE) and to study antioxidant, anti-tyrosinase and anti-bacterial activities and its freeze–thaw stability as well. To achieve optimal conditions for producing electrospun gelatin fiber, the concentration of gelatin was adjusted to 30% w/v in a co-solvent system of acetic acid/water (9:1 v/v) with a feed rate of 3 mL/h and an applied voltage of 15 kV. The lowest percent loading of 5% (w/v) CE in gelatin nanofiber exhibited the highest DPPH radical scavenging activity of 94% and the highest inhibition of tyrosinase enzyme of 35%. Moreover, the inhibition zones for antibacterial activities against S. aureus and S. epidermidis were 7.77 ± 0.21 and 7.73 ± 0.12 mm, respectively. The freeze–thaw stability of CE in electrospun gelatin nanofiber was significantly different (p < 0.05) after the 4th cycle as compared to CE. Electrospun gelatin nanofiber containing CE also showed the capacity of the release of bioactive ingredients possessing anti-oxidant properties and, therefore, it could potentially be used for face masks.

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.

Polycaprolactone nanofibers loaded oxytetracycline hydrochloride and zinc oxide for treatment of periodontal disease

Periodontal diseases (PD) are mixed bacterial infections caused by microorganisms that colonize the tooth surface, leading to destructions at tooth-supporting tissues. Several local delivery systems, as nanofibers, have been developed for the treatment of PD. The purpose of the present study was developing polycaprolactone (PCL) nanofibers incorporating two antibacterial agents, OTC and ZnO, for use in the treatment of PD. Nanofibers were produced by electrospinning method: PCL loaded with ZnO (PCL-Z), PCL loaded with OTC (PCL-OTC), PCL loaded with OTC and ZnO (PCL-OTCz) and pristine PCL (PCL-P). The nanofibers were characterized physicochemically using different techniques. In addition, in vitro study of the OTC release from the nanofibers was performed. The PCL-OCT showed sustained release of the drug up to 10 h, releasing 100% of OTC. However, the PCL-OTCz nanofiber showed a slow release of OTC up to 120 h (5th day) with 54% of drug retention. The cytotoxicity assay showed that PCL-OTC nanofiber was slightly cytotoxic after 48 h and the other nanofibers were non-cytotoxic. The antibacterial activity of the nanofibers was evaluated by qualitative and quantitative analysis and against mixed bacterial culture, composed of four Gram-negative anaerobic bacteria involved in periodontal diseases. The disk diffusion method showed that the PCL-OTC displayed higher inhibition zone than PCL-OTCz (p < 0.001). The quantitative analysis, evaluated by broth culture, showed that the PCL-OTC and PCL-OTCz exhibited excellent activity against a mixed bacterial culture with growth inhibition of 98.0% and 97.5%, respectively. Based on these results, the PCL-OTCz nanofibers developed have great potential as a drug delivery system for the PD treatment.

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.

Impact of PCL nanofiber mat structural properties on hydrophilic drug release and antibacterial activity on periodontal pathogens

Electrospinning enables to design and manufacture novel drug delivery systems capable of advancing the local antibacterial therapy. In this study, two hydrophilic drugs - metronidazole and ciprofloxacin hydrochloride - were loaded both individually and in combination into hydrophobic poly(ε-caprolactone) (PCL) matrix using electrospinning. We aimed to develop prolonged release drug delivery systems suitable for the treatment of periodontal diseases and understand how different rarely studied structural features, such as nanofiber mat thickness, surface area, wettability, together with intrinsic properties, like solid state and localization of incorporated drugs in nanofibers, affect the drug release. Furthermore, the safety of nanofiber mats was assessed in vitro on fibroblasts, and their antibacterial activity was tested on selected strains of periodontopathogenic bacteria. The results showed that the structural properties of nanofiber mat are crucial in particular drug-polymer combinations, affecting the drug release and consequently the antibacterial activity. The hydrophobicity of a PCL nanofiber mat and its thickness are the key characteristics in prolonged hydrophilic drug release, but only when wetting is the rate-limiting step for the drug release. Combination of drugs showed beneficial effects by inhibiting the growth of all tested pathogenic bacterial strains important in periodontal diseases.

Electrospun cellulose acetate doped with astaxanthin derivatives from Haematococcus pluvialis for in vivo anti-aging activity

This research aims to study the release, in vivo anti-aging activity against Caenorhabditis elegans and stability of astaxanthins in a crude acetone extract of Haematococcus pluvialis from electrospun cellulose acetate (CA) nanofibers. The content and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity of astaxanthins in the crude extract were also determined. The content of astaxanthins was reported in terms of total carotenoid content (TCC) and found to be 10.75 ± 0.16 mg gcE⁻¹. IC₅₀ of DPPH radical scavenging activity for astaxanthins was 233.33 ± 4.18 μg mL⁻¹. It has been well known that astaxanthins are very unstable under environmental conditions, so the electrospinning technique was used to enhance their stability. In order to fabricate CA nanofibers containing a crude acetone extract of H. pluvialis, various solvent systems and percent loading of the crude acetone extract were studied. The optimal solvent system for fabrication of CA nanofibers was the acetone/dimethylformamide (DMF) system (2 : 1 v/v) with incorporation of 0.25% v/v Tween80, resulting in good morphology of CA nanofibers with av. 420 nm diameter. The loading efficiency (%) of the crude astaxanthins extract was 5% w/w of CA. With regard to the results of the in vivo oxidative stress assay, C. elegans pre-treated with 200 μg mL⁻¹ of the crude extract had a survival percent of 56 after administration of 250 mM of paraquat for 8 h. Under phosphate-buffered saline (pH 7.4) containing 10% v/v acetone, the release of astaxanthins from the CA nanofibers loaded with the crude extract exhibited a prolonged profile. The stability of astaxanthins in electrospun CA nanofibers was examined using the freeze–thaw cycle testing through a DPPH radical scavenging assay. It was found that their stability was significantly different (P < 0.05) after the 12^th freeze–thaw cycle compared with the crude extract.

The astaxanthin derivatives loaded CA fibers enhanced the percentage survival of C. elegans upto 56.17% after adding paraquat and it stability increased with 1.7 times by using DPPH scavenging assay.

Use of Polycaprolactone Electrospun Nanofibers as a Coating for Poly(methyl methacrylate) Bone Cement

Poly(methyl methacrylate) (PMMA) bone cement has limited biocompatibility. Polycaprolactone (PCL) electrospun nanofiber (ENF) has many applications in the biomedical field due to its excellent biocompatibility and degradability. The effect of coating PCL ENF on the surface topography, biocompatibility, and mechanical strength of PMMA bone cement is not currently known. This study is based on the hypothesis that the PCL ENF coating on PMMA will increase PMMA roughness leading to increased biocompatibility without influencing its mechanical properties. This study prepared PMMA samples without and with the PCL ENF coating, which were named the control and ENF coated samples. This study determined the effects on the surface topography and cytocompatibility (osteoblast cell adhesion, proliferation, mineralization, and protein adsorption) properties of each group of PMMA samples. This study also determined the bending properties (strength, modulus, and maximum deflection at fracture) of each group of PMMA samples from an American Society of Testing Metal (ASTM) standard three-point bend test. This study found that the ENF coating on PMMA significantly improved the surface roughness and cytocompatibility properties of PMMA (p < 0.05). This study also found that the bending properties of ENF-coated PMMA samples were not significantly different when compared to those values of the control PMMA samples (p > 0.05). Therefore, the PCL ENF coating technique should be further investigated for its potential in clinical applications.

Core/shell poly(ethylene oxide)/Eudragit fibers for site-specific release

Electrospinning was used to prepare core/shell fibers containing the active pharmaceutical ingredients indomethacin (IMC) or mebeverine hydrochloride (MB-HCl). The shell of the fibers was fabricated from the pH sensitive Eudragit S100 polymer, while the drug-loaded core was based on the mucoadhesive poly(ethylene oxide) (PEO). Three different drug loadings (from 9 to 23% (w/w) of the core mass) were prepared, and for MB-HCl two different molecular weights of PEO were explored. The resultant fibers generally comprise smooth cylinders, although in some cases defects such as surface particles or flattened or merged fibers were visible. Transmission electron microscopy showed all the systems to have clear core and shell compartments. The drugs are present in the amorphous physical form in the fibers. Dissolution tests found that the fibers can effectively prevent release in acidic conditions representative of the stomach, particularly for the acidic indomethacin. After transfer to a pH 7.4 medium, sustained release over between 6 and 22h is observed. Given the mucoadhesive nature of the PEO core, after dissolution of the shell the fibers will be able to adhere to the walls of the intestinal tract and give sustained local drug release. This renders them promising for the treatment of conditions such as irritable bowel disease and colon cancer.

Long-Term Sustained Ciprofloxacin Release from PMMA and Hydrophilic Polymer Blended Nanofibers

Nanofibers represent an attractive novel drug delivery system for prolonged and controlled release. However, sustained release of hydrophilic drugs, like ciprofloxacin hydrochloride (CIP), from polymeric nanofibers is not an easy task. The present study investigates the effect of different hydrophobic polymers (PCL and PMMA) alone in monolithic nanofibers or with hydrophilic polymers (PVA, PEO, and chitosan) in blended nanofibers aiming to achieve sustained CIP release. CIP release from PCL nanofibers was 46% and from PMMA just 1.5% over 40 day period. Thus, PMMA holds great promise for modification of CIP release from blended nanofibers. PMMA blends with 10% PEO, PVA, or chitosan were used to electrospin nanofibers from solution in the mixture of acetic and formic acid. These nanofibers exhibited different drug-release profiles: PEO containing nanofiber mats demonstrated high burst effect, chitosan containing mats revealed very slow gradual release, and PVA containing mats yielded smaller burst effect with favorable sustained release. We have also shown that gradual sustain release of antibiotic like CIP can be additionally tuned over 18 days with various blend ratios of PMMA with PVA or chitosan reaching almost 100%. A mathematical model in agreement with the experimental observation revealed that the sustained CIP release from the blended nanofibers corresponded to the two-stage desorption process.