Development of electrosprayed mucoadhesive chitosan microparticles

Development and optimization of electrosprayed vitamin C - chitosan nanoparticle: A CCD-RSM approach and characterization of bioactive encapsulant

Electrospraying for Vitamin C (VC) encapsulation in Chitosan (Cs) nanoparticles was investigated and particle size, zeta potential, loading capacity (LC%) and encapsulation efficiency (EE%) were examined. Cs concentration (1-2% w/v) and voltage (21-25 kV) were varied with VC (0.25-0.75 w/w Cs). Twenty experiments in a face-centered CCD-RSM design were evaluated. ANOVA suggested voltage and Cs concentration as significant factors for particle size and VC content affected zeta, LC and EE%. RSM proposed optimum processing parameter at 2% Cs, 0.746 VC: Cs mass ratio and 21 kV voltage with 251.1 ± 59.03 nm particle size, 36.6% LC and an EE of 85.42%. Encapsulated particles were subjected to release behaviour, antioxidant property and analyzed through FTIR, DSC and XRD. Encapsulated VC had better antibacterial properties than Cs nanoparticles, and comparable VC retention in apple juice showed its effectiveness. Overall, nanoencapsulation of VC using electrospraying was successfully developed to be used in numerous food processing applications.

Crosslinked chitosan-montmorillonite composite and its magnetized counterpart for the removal of basic fuchsin from wastewater: Parametric optimization using Box-Behnken design

Treating wastewater polluted with organic dyestuffs is still a challenge. In that vein, facile synthesis of a structurally simple composite of chitosan with montmorillonite (CS-MMT) using glutaraldehyde as a crosslinker and the magnetized analogue (MAG@CS-MMT) was proposed as versatile adsorbents for the cationic dye, basic Fuchsin (FUS). Statistical modeling of the adsorption process was mediated using Box-Behnken (BB) design and by varying the composite dose, pH, [FUS], and contact time. Characterization of both composites showed an enhancement of surface features upon magnetization, substantiating a better FUS removal of the MAG@CS-MMT (%R = 98.43 %) compared to CS-MMT (%R = 68.02 %). The surface area analysis demonstrates that MAG@CS-MMT possesses a higher surface area, measuring 41.54 m2/g, and the surface analysis of the magnetized nanocomposite, conducted using FT-IR and Raman spectroscopies, proved the presence of FeO peaks. In the same context, adsorption of FUS onto MAG@CS-MMT fitted-well to the Langmuir isotherm model and the maximum adsorption capacities (qm) were 53.11 mg/g for CS-MMT and 88.34 mg/g for MAG@CS-MMT. Kinetics investigation shows that experimental data fitted well to the pseudo-second order (PSO) model. Regeneration study reveals that MAG@CS-MMT can be recovered effectively for repeated use with a high adsorption efficiency for FUS.

Chitosan-based oral hydrogel formulations of β-galactosidase to improve enzyme supplementation therapy for lactose intolerance

β-Galactosidase supplementation plays an important role in the life of people with lactose intolerance. However, these formulations are rendered ineffective by the low pH and pepsin in the stomach and pancreatic proteases in the intestine. Therefore, it is necessary to develop oral transport systems for carrying this enzyme in the active form up to the intestine, where the lactose digestion occurs. In this research, a new hydrogel was developed that could potentially be used for enzyme supplement therapy. In this regard, the chitosan-based β-Gal formulations described in the manuscript are an alternative long-acting preparation to the so far available preparations that allow for enzyme protection and mucosal targeting. These hydrogels were prepared from chitosan and polyethylene glycol and contained a covalently immobilized β-galactosidase from Aspergillus oryzae. The β-galactosidase in the hydrogel was protected from degradation in a gastric medium at a pH of 2.5 and retained 75 % of its original activity under subsequent intestinal conditions. In the case of a simulated gastric fluid with a pH of 1.5, a copolymer containing methacrylic acid functional groups was sufficient to protect the hybrid hydrogel from the extremely acidic pH. In addition, the surface of the hydrogel was chemically modified with thiol and amidine groups, which increased the binding to intestinal mucin by 20 % compared with the unmodified hydrogel. These results represent a promising approach for oral transport as a reservoir for β-galactosidase in the small intestine to reduce the symptoms of hypolactasia.

A novel self-supportive thin film based on graphene oxide reinforced chitosan nano-biocomposite for thin film microextraction of fluoxetine in biological and environmental samples

In this research, for the first time, graphene oxide doped chitosan (GO/CS) nano-biocomposite (NBC) is designed and prepared as a novel self-supportive thin layer for thin film microextraction (TFME) of fluoxetine (FLX) followed by determination applying HPLC-UV-Vis. The properties of the prepared self-supportive thin film were characterized applying ATR-FTIR, FESEM, and XRD techniques. The extraction capability of GO/CS NBC toward FLX has been evaluated, and the obtained results revealed that incorporation of GO into CS has led to higher extraction efficiency in comparison to the CS thin film. After optimizing the effective factors on the extraction efficiency, the figures of merit for the developed method have been evaluated for determination of FLX in various samples. Accordingly, the method's linearity is in the range of 0.4-800 ng mL-1 (R2 = 0.996), 4-1000 ng mL-1 (R2 = 0.994), 4-1000 ng mL-1 (R2 = 0.990), and 6-1000 ng mL-1 (R2 = 0.993) for deionized water, wastewater, urine and plasma samples, respectively. The limits of detection based on 3 S/N definition was 0.1, 1, 1 and 1.6 ng mL-1 for deionized water, wastewater, urine, and plasma samples, respectively. The repeatability of the developed method has been investigated in the term of intra-day, inter-day and inter-thin film precision and RSD% values for six replicate experiments were obtained 8.6%, 8.4% and 5.7%, respectively. The accuracy of the developed method has been investigated by extraction of FLX from spiked wastewater, plasma and urine samples and the relative recoveries of 104.4%, 87.3% and 82.4% have been resulted, respectively.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Cationic Chitosan Derivatives for the Inactivation of HIV-1 and SARS-CoV-2 Enveloped Viruses

Cationic chitosan derivatives have been widely studied as potential antimicrobial agents. However, very little is known about their antiviral activity and mode of action against enveloped viruses. We investigated the ability of hydroxypropanoic acid-grafted chitosan (HPA-CS) and N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC) to inactivate enveloped viruses like the human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The membrane-disrupting potential of the chitosan derivatives was initially investigated in a hemolysis assay. At 1.0 mg/mL, about 80% hemolysis was observed for the cationic chitosan derivatives, which was significant when compared to almost no membrane-disrupting activity by the unmodified chitosan. Virus inhibition was evaluated using the luciferase-based antiviral assay against the HIV-1 NL4.3 virus (400 TCID). The IC50 of HPA-CS was 4.109 mg/mL, while the HTCC showed a higher antiviral activity at an IC50 = 0.225 mg/mL. For practical application, the antiviral efficacies of the HTCC-coated and uncoated nonmedical masks were evaluated for SARS- CoV-2 virus capture. The coated masks demonstrated an almost excellent performance with nearly 100% viral inhibition compared to less than 60% inhibition by the uncoated masks. Molecular docking predictions suggest that the HTCC polymers interact with the viral spike protein, blocking the coronavirus interaction with the target host cell's angiotensin-converting enzyme 2 cellular receptors.

Chitosan-Based Particulate Carriers: Structure, Production and Corresponding Controlled Release

The state of the art in the use of chitosan (CS) for preparing particulate carriers for drug delivery applications is reviewed. After evidencing the scientific and commercial potentials of CS, the links between targeted controlled activity, the preparation process and the kinetics of release are detailed, focusing on two types of particulate carriers: matrix particles and capsules. More precisely, the relationship between the size/structure of CS-based particles as multifunctional delivery systems and drug release kinetics (models) is emphasized. The preparation method and conditions greatly influence particle structure and size, which affect release properties. Various techniques available for characterizing particle structural properties and size distribution are reviewed. CS particulate carriers with different structures can achieve various release patterns, including zero-order, multi-pulsed, and pulse-triggered. Mathematical models have an unavoidable role in understanding release mechanisms and their interrelationships. Moreover, models help identify the key structural characteristics, thus saving experimental time. Furthermore, by investigating the close relation between preparation process parameters and particulate structural characteristics as well as their effect on release properties, a novel "on-demand" strategy for the design of drug delivery devices may be developed. This reverse strategy involves designing the production process and the related particles' structure based on the targeted release pattern.

Current and emerging applications of saccharide-modified chitosan: a critical review

Chitin, as the main component of the exoskeleton of Arthropoda, is a highly available natural polymer that can be processed into various value-added products. Its most important derivative, i.e., chitosan, comprising β-1,4-linked 2-amino-2-deoxy-β-d-glucose (deacetylated d-glucosamine) and N-acetyl-d-glucosamine units, can be prepared via alkaline deacetylation process. Chitosan has been used as a biodegradable, biocompatible, non-antigenic, and nontoxic polymer in some in-vitro applications, but the recently found potentials of chitosan for in-vivo applications based on its biological activities, especially antimicrobial, antioxidant, and anticancer activities, have upgraded the chitosan roles in biomaterials. Chitosan approval, generally recognized as a safe compound by the United States Food and Drug Administration, has attracted much attention toward its possible applications in diverse fields, especially biomedicine and agriculture. Even with some favorable characteristics, the chitosan's structure should be customized for advanced applications, especially due to its drawbacks, such as low drug-load capacity, low solubility, high viscosity, lack of elastic properties, and pH sensitivity. In this context, derivatization with relatively inexpensive and highly available mono- and di-saccharides to soluble branched chitosan has been considered a "game changer". This review critically reviews the emerging technologies based on the synthesis and application of lactose- and galactose-modified chitosan as two important chitosan derivatives. Some characteristics of chitosan derivatives and biological activities have been detailed first to understand the value of these natural polymers. Second, the saccharide modification of chitosan has been discussed briefly. Finally, the applications of lactose- and galactose-modified chitosan have been scrutinized and compared to native chitosan to provide an insight into the current state-of-the research for stimulating new ideas with the potential of filling research gaps.

Natural Pyranosyl Materials: Potential Applications in Solid-State Batteries

Solid-state batteries have become one of the hottest research areas today, due to the use of solid-state electrolytes enabling the high safety and energy density. Because of the interaction with electrolyte salts and the abundant ion transport sites, natural polysaccharide polymers with rich functional groups such as -OH, -OR or -COO^- etc. have been applied in solid-state electrolytes and have the merits of possibly high ionic conductivity and sustainability. This review summarizes the recent progress of natural polysaccharides and derivatives for polymer electrolytes, which will stimulate further interest in the application of polysaccharides for solid-state batteries.

Buccal delivery of small molecules and biologics: Of mucoadhesive polymers, films, and nanoparticles - An update

Buccal delivery of small and large molecules is an attractive route of administration that has been studied extensively over the past few decades. This route bypasses first-pass metabolism and can be used to deliver therapeutics directly to systemic circulation. Moreover, buccal films are efficient dosage forms for drug delivery due to their simplicity, portability, and patient comfort. Films have traditionally been formulated using conventional techniques, including hot-melt extrusion and solvent casting. However, newer methods are now being exploited to improve the delivery of small molecules and biologics. This review discusses recent advances in buccal film manufacturing, using the latest technologies, such as 2D and 3D printing, electrospraying, and electrospinning. This review also focuses on the excipients used in the preparation of these films, with emphasis on mucoadhesive polymers and plasticizers. Along with advances in manufacturing technology, newer analytical tools have also been used for the assessment of permeation of the active agents across the buccal mucosa, the most critical biological barrier and limiting factor of this route. Additionally, preclinical and clinical trial challenges are discussed, and some small molecule products already on the market are explored.

Biotechnologically produced chitosans with nonrandom acetylation patterns differ from conventional chitosans in properties and activities

Chitosans are versatile biopolymers with multiple biological activities and potential applications. They are linear copolymers of glucosamine and N-acetylglucosamine defined by their degree of polymerisation (DP), fraction of acetylation (F_A), and pattern of acetylation (PA). Technical chitosans produced chemically from chitin possess defined DP and F_A but random PA, while enzymatically produced natural chitosans probably have non-random PA. This natural process has not been replicated using biotechnology because chitin de-N-acetylases do not efficiently deacetylate crystalline chitin. Here, we show that such enzymes can partially N-acetylate fully deacetylated chitosan in the presence of excess acetate, yielding chitosans with F_A up to 0.7 and an enzyme-dependent non-random PA. The biotech chitosans differ from technical chitosans both in terms of physicochemical and nanoscale solution properties and biological activities. As with synthetic block co-polymers, controlling the distribution of building blocks within the biopolymer chain will open a new dimension of chitosan research and exploitation.

Green synthesis of multifunctional ZnO/chitosan nanocomposite film using wild Mentha pulegium extract for packaging applications

Following the global corona virus pandemic and environmental contamination caused by chemical plastic packaging, awareness of the need for environmentally friendly biofilms and antibacterial coatings is increasing. In this study, a biodegradable hybrid film, comprising of green-synthesized zinc oxide nanoparticles (ZnO NPs) with a chitosan (CS) matrix, was fabricated using a simple casting procedure. The ZnO NPs were synthesized using wild Mentha pulegium extract, and the synthesized NPs and films were characterized using different approaches. The structural, morphological, mechanical, antibacterial, and optical properties, as well as the hydrophilicity, of the prepared samples were investigated using various techniques. Gas chromatography-mass spectrometry measurements revealed the presence of phenolic compounds in the M. pulegium extract. In addition, a strong coordination connection between Zn²⁺ and the chitosan matrix was confirmed, which resulted in a good dispersion of ZnO in the chitosan film. The surface of the composite films was transparent, smooth, and uniform, and the flexible bio-based hybrid films exhibited significant antibacterial and antioxidant characteristics, strong visible emission in the 480 nm region, and UV-blocking properties. The ZnO/CS films displayed a potential to extend the shelf life of fruits by up to eight days when stored at 23°C, and also acted as an acceptable barrier against oxygen and water. The biodegradable ZnO/CS film is expected to keep fruit fresher than general chemical plastic films and be used for the packaging of active ingredients.

Phenylboronic acid modified hydrogel materials and their potential for use in contact lens based drug delivery

The use of hydrogel-based contact lens materials holds promise for ophthalmic drug delivery by increasing drug residence time, improving drug bioavailability, reducing administration frequency, and enhancing special site targeting. Issues such as ease of manufacturing, lens comfort and appropriate release kinetics must be considered. Furthermore, the high water content of hydrogel materials can result in rapid and poorly controlled release kinetics. Herein, we modified common hydrogels used in contact lens manufacturing with phenylboronic acid (PBA). PBA addresses these material design issues since boronate esters are easily formed when boron acid and diols interact, opening up a pathway for simple modification of the model lens materials with saccharide based wetting agents. The wetting agents have the potential to improve lens comfort. Furthermore, the hydrophobicity of PBA and the presence of diols can be useful to help control drug release kinetics. In this work, polymerizable 3-(acrylamido)phenylboronic acid (APBA) was synthesized and incorporated into various hydrogels used in contact lens applications, including poly(2-hydroxyethylmethacrylate) (PHEMA), polyvinylpyrrolidone (PVP) and poly(N,N-dimethyl acrylamide) (PDMA) using UV induced free radical polymerization. The APBA structure and its incorporation into the hydrogel materials were confirmed by NMR and FTIR. The materials were shown to interact with and bind wetting agents such as hyaluronan (HA) and hydroxypropyl guar (HPG) by simple soaking in an aqueous solution. The equilibrium water content of the modified materials was characterized, demonstrating that most materials are still in the appropriate range after the introduction of the hydrophobic PBA. The release of three model ophthalmic drugs with varying hydrophilicity, atropine, atropine sulfate and dexamethasone, was examined. The presence of PBA in the materials was found to promote sustained drug release due to its hydrophobic nature. The results suggest that the modification of the materials with PBA was able to not only provide a mucoadhesive property that enhanced wetting agent interactions with the materials, but had the potential to alter drug release. Thus, the modification of contact lens materials with mucoadhesive functionality may be useful in the design of hydrogel contact lenses for ophthalmic drug release and wetting agent binding.

Chitosan: A Promising Multifunctional Cosmetic Ingredient for Skin and Hair Care

The cosmetic industry has an undeniable need to design and develop new ecosustainable products to respond to the demands of consumers and international regulations. This requires substituting some traditional ingredients derived from petrochemical sources with new ones with more ecofriendly profiles. However, this transition towards the use of green ingredients in the cosmetic industry cannot compromise the effectiveness of the obtained products. Emerging ingredients in this new direction of the cosmetic industry are chitosan and its derivatives, which combine many interesting physicochemical and biological properties for the fabrication of cosmetic products. Thus, the use of chitosan opens a promising future path to the design of cosmetic formulations. In particular, chitosan’s ability for interacting electrostatically with negatively charged substrates (e.g., skin or damaged hair), resulting in the formation of polymeric films which contribute to the conditioning and moisturizing of cosmetic substrates, makes this polymer an excellent candidate for the design of skin and hair care formulations. This review tries to provide an updated perspective on the potential interest of chitosan and its derivatives as ingredients of cosmetics for skin and hair care.

Modulation of soy protein isolate gel properties by a novel "two-step" gelation process: Effects of pre-aggregation with different divalent sulfates

A novel pre-aggregation process prior to gelation was applied to modulate the aggregation and gelation pathway of soy protein isolate (SPI). SPI dispersions were pre-aggregated with CaSO₄, MgSO₄ or ZnSO₄ at 0-15 mM and then gelled by adding CaSO₄ up to a final salt concentration of 35 mM. Compared with the sample without pre-aggregation, the storage modulus of SPI gels pre-aggregated with 10 mM CaSO₄, 10 mM MgSO₄, and 2.5 mM ZnSO₄ were increased by 50.5%, 35.7%, and 63.6%, respectively. The fracture stress, texture profile analysis parameters, and water holding capacity were markedly improved by an appropriate level of pre-aggregation. To a certain extent, pre-aggregation could promote the formation of uniform structure with thicker strands, whereas over-aggregation resulted in a coarser network, which was correlated with the volume-mean diameter (D_4,3) of pre-aggregated SPI particles. The results are of great value for further understanding of gelation mechanism of proteins.

Effects of Selenium Nanoparticles on Preventing Patulin-Induced Liver, Kidney and Gastrointestinal Damage

Patulin (PAT) is a toxic fungal metabolite, and oxidative damage was proved to be its important toxicity mechanism. Selenium nanoparticles (SeNPs) were prepared by reducing sodium selenite with chitosan as a stabilizer and used for preventing PAT-induced liver, kidney and gastrointestinal damage. SeNPs have good dispersibility, in vitro antioxidant activity, and are much less cytotoxic than sodium selenite. Cell culture studies indicated that SeNPs can effectively alleviate PAT-induced excessive production of intracellular ROS, the decline of glutathione peroxidase activity, and the suppression of cell viability. Evaluation of serum biochemical parameters, histopathology, oxidative stress biomarkers and activities of antioxidant enzymes in a mouse model showed that pre-treatment with SeNPs (2 mg Se/kg body weight) could ameliorate PAT-induced oxidative damage to the liver and kidneys of mice, but PAT-induced gastrointestinal oxidative damage and barrier dysfunction were not recovered by SeNPs, possibly because the toxin doses suffered by the gastrointestinal as the first exposed tissues exceeded the regulatory capacity of SeNPs. These results suggested that a combination of other strategies may be required to completely block PAT toxicity.

Current Advances in Multifunctional Nanocarriers Based on Marine Polysaccharides for Colon Delivery of Food Polyphenols

Inflammatory bowel disease (IBD) has been considered as a chronic disease that is difficult to cure and needs lifelong treatment. Marine polysaccharides with good biocompatibility and biodegradability, mucoadhesion, sensitivity to external stimuli, and targeting ability can be used as wall materials for oral colon-targeted delivery of polyphenols in nutrition intervention of IBD. This manuscript reviewed the latest progress in the design, preparation, and characterization of marine polysaccharides-derived multifunctional nanocarriers for polyphenol colon delivery. Chitosan, sodium alginate, chondroitin sulfate, and hyaluronic acid were discussed in the preparation of polyphenol delivery systems. The design strategy, synthesis methods, and structure characterization of multifunctional polyphenol carriers including stimuli-responsive nanocarriers, mucoadhesive and mucus-penetrating nanocarriers, colon targeted nanocarriers, and bioactive compounds codelivery nanocarriers were reviewed in the alleviation of IBD. The research perspectives in the preparation and characterization of delivery carriers using marine polysaccharide as materials were proposed for their potential application in food bioactive components.

Nanoparticles as an effective drug delivery system in COVID-19

Background

The global healthcare sector has been dealing with a situation known as a novel severe acute respiratory syndrome (SARS-CoV-2) since the end of 2019. Covid-19 is an acronym for Covid-19 (Coronavirus Disease- 2019). It causes a respiratory infection that includes cold, sneezing and coughing, and pneumonia. In the case of an animal, it causes diarrhea and upper respiratory diseases. Covid-19 transmitted human to human via airborne droplets. First Covid-19 emerged in Wuhan market China and it spread rapidly throughout the World. As we know nanoparticles are a novel drug delivery system. They have various advantageous effects like increasing the efficacy of the drug, safety, etc. In this review, we study about the nanoparticles and summarize how it is effective during drug delivery system in Covid-19. Chitosan is a much focused biopolymeric nanoparticle. It delivers drugs to the specific target site. In a recent health crisis, chitosan nanoparticles are one of the ways to release drugs of Covid-19, and specifically in the lungs of the affected patients. We studied and extracted our data from various research papers, review papers, and some other articles.

Objective

The main goal is to study the nanoparticles and their future aspects which is an effective drug delivery system in Covid-19.

Methods

The bibliographic search was done through a systematic search. The terms “Nanoparticles”, “Covid-19 ”, “Drug delivery” etc. were used to search the databases/search engines like “Google Scholar”, “NCBI”, “PubMed”, “Science Direct” etc. These databases and search engines used here perform the limited criteria of search to conduct a systematic literature survey for the study and report writing. All the text from the articles and research papers were studied and analyzed. The various articles and research papers were used in writing this report and all of which are mentioned in the reference section of this report.

Conclusion

Our current studies reveal that nanoparticles may prove very helpful in the delivery of drugs for Covid-19 treatment. Many cases showed that patients, where drugs are delivered with the help of nanoparticles, produced very few side effects.

A review on chitosan and chitosan-based bionanocomposites: Promising material for combatting global issues and its applications

Over the last few years, several attempts have been made to replace petrochemical products with renewable and biodegradable components. The most challenging part of this approach is to obtain bio-based materials with properties and functions equivalent to those of synthetic products. Various naturally occurring polymers such as starch, collagen, alginate, cellulose, and chitin represent attractive candidates as they could reduce dependence on synthetic products and consequently positively impact the environment. Chitosan is also a unique bio-based polymer with excellent intrinsic properties. It is known for its anti-bacterial and film-forming properties, has high mechanical strength and good thermal stability. Nanotechnology has also applied chitosan-based materials in its most recent achievements. Therefore, numerous chitosan-based bionanocomposites with improved physical and chemical characteristics have been developed in an eco-friendly and cost-effective approach. This review discusses various sources of chitosan, its properties and methods of modification. Also, this work focuses on diverse preparation techniques of chitosan-based bionanocomposites and their emerging application in various sectors. Additionally, this review sheds light on future research scope with some drawbacks and challenges to motivate the researchers for future outstanding research works.

Polymeric nano- and microparticulate drug delivery systems for treatment of biofilms

Now-a-days healthcare systems face great challenges with antibiotic resistance and low efficacy of antibiotics when combating pathogenic bacteria and bacterial biofilms. Administration of an antibiotic in its free form is often ineffective due to lack of selectivity to the infectious site and breakdown of the antibiotic before it exerts its effect. Therefore, polymeric delivery systems, where the antibiotic is encapsulated into a formulation, have shown great promise, facilitating a high local drug concentration at the site of infection, a controlled drug release and less drug degradation. All this leads to improved therapeutic effects and fewer systemic side effects together with a lower risk of developing antibiotic resistance. Here, we review and provide a comprehensive overview of polymer-based nano- and microparticles as carriers for antimicrobial agents and their effect on eradicating bacterial biofilms. We have a main focus on polymeric particulates containing poly(lactic-co-glycolic acid), chitosan and polycaprolactone, but also strategies involving combinations of these polymers are included. Different production techniques are reviewed and important parameters for biofilm treatment are discussed such as drug loading capacity, control of drug release, influence of particle size and mobility in biofilms. Additionally, we reflect on other promising future strategies for combating biofilms such as lipid-polymer hybrid particles, enzymatic biofilm degradation, targeted/triggered antibiotic delivery and future alternatives to the conventional particles.

Electrospraying as a novel process for the synthesis of particles/nanoparticles loaded with poorly water-soluble bioactive molecules

Hydrophobicity and low aqueous-solubility of different drugs/nutraceuticals remain a persistent challenge for their development and clinical/food applications. A range of nanotechnology strategies have been implemented to address this issue, and amongst which a particular emphasis has been made on those that afford an improved biological performance and tunable release kinetic of bioactives through a one-step process. More recently, the technique of electrospraying (or electrohydrodynamic atomization) has attained notable impulse in virtue of its potential to tune attributes of nano/micro-structured particles (e.g., porosity, particle size, etc.), rendering a near zero-order release kinetics, diminished burst release manner, as well as its simplicity, reproducibility, and applicability to a broad spectrum of hydrophobic and poorly water-soluble bioactives. Controlled morphology or monodispersity of designed particles could be properly obtained via electrospraying, with a high encapsulation efficiency and without unfavorable denaturation of thermosensitive bioactives upon encapsulation. This paper overviews the recent technological advances in electrospraying for the encapsulation of low queues-soluble bioactive agents. State-of-the-art, advantages, applications, and challenges for its implementation in pharmaceutical/food researches are also discussed.

Models to evaluate the barrier properties of mucus during drug diffusion

Mucus is widely disseminated in the nasal cavity, oral cavity, respiratory tract, eyes, gastrointestinal tract, and reproductive tract to prevent the invasion of pathogenic bacteria and toxins. The mucus layer through its continuous secretion can prevent the passage of macromolecular substances such as pathogenic bacteria and toxins, thereby reducing the occurrence of inflammation. Without a doubt, mucus also hinders oral absorption. The physiological and biochemical properties of intestinal mucus and the different types of mucus barrier models need to be predominated. To find ways to increase the bioavailability of drugs in the future, this article summarizes mucus composition, barrier properties, mucus models, and mucoadhesive/mucopenetrating particles to highlight the information they can afford. Collectively, the review seeks to provide a state-of-the-art roadmap for researchers who must contend with this critical barrier to drug delivery.

Electrohydrodynamic Processing of Potato Protein into Particles and Fibers

Potato protein particles and fibers were produced using electrohydrodynamic processing (electrospray and electrospinning). The effect of different solvents and protein concentration on the morphology of the potato protein particles and fibers was investigated. Electrosprayed particles with average diameters ranging from 0.3 to 1.4 µm could be obtained using water and mixtures of water: ethanol (9:1) and water:glycerol (9:1). Electrosprayed particles were also obtained using the solvent hexafluoro-2-propanol (HFIP) at a protein concentration of 5% wt/v. For protein concentrations above 10% wt/v, using HFIP, electrospun fibers were produced. The release of vitamin B12, as a model bioactive compound, from potato protein electrospun fibers, was also investigated, demonstrating their potential to be utilized as encapsulation and delivery systems.

Electrospray: More than just an ionization source

Electrospraying (ES) is a potential-driven process of liquid atomization, which is employed in the field of analytical chemistry, particularly as an ionization technique for mass spectrometric analyses of biomolecules. In this review, we demonstrate the extraordinary versatility of the electrospray by overviewing the specifics and advanced applications of ES-based processing of low molecular mass compounds, biomolecules, polymers, nanoparticles, and cells. Thus, under suitable experimental conditions, ES can be used as a powerful tool for highly controlled deposition of homogeneous films or various patterns, which may sometimes even be organized into 3D structures. We also emphasize its capacity to produce composite materials including encapsulation systems and polymeric fibers. Further, we present several other, less common ES-based applications. This review provides an insight into the remarkable potential of ES, which can be very useful in the designing of innovative and unique strategies.

Sublingual indocyanine green films for non-invasive swallowing assessment and inflammation detection through NIR/SWIR optical imaging

Indocyanine green (ICG) is the most commonly used FDA-approved agent for clinical optical imaging, administered through injections only, due to its poor membrane permeability. Although ICG has vast potential for non-invasive non-radioactive imaging in patients, the clinical applications are limited by the invasive administration and short half-life in blood circulation. To expand the clinical value of ICG, non-toxic chitosan-based ICG-loaded films were designed for sublingual administration for near-infrared (NIR) and short-wave infrared (SWIR) optical imaging. Two film formulations were developed with different ICG release rates. Mold-casted self-emulsifying films rapidly released ICG (80% in 4 h) in the form of nanosized droplets, which were mostly swallowed and produced significant contrast of upper digestive tract to enable in vivo swallowing evaluations using NIR/SWIR imaging. Regular films released ICG slowly (80% in 25 h), allowing for steady absorption of ICG to systemic circulation. Inflammation in mouse feet was detected within 30 min after sublingual administration with a 1.43-fold fluorescence increase within 1 h at the inflammation sites, comparable to a 1.76-fold increase through intravenous injection. Administering ICG using sublingual films displayed notable potential for non-invasive diagnosis and monitoring of inflammatory conditions and swallowing disorders, addressing a current need for alternatives to ICG parenteral administration.

Thiolated chitosans: Are Cys-Cys ligands key to the next generation?

The potential of Cys-Cys ligands for the development of a novel type of S-protected thiomers was evaluated. S-protected thiomers chitosan-N-acetylcysteine-mercaptonicotinamide (CS-NAC-MNA) and chitosan-N-acetylcysteine-N-acetylcysteine (CS-NAC-NAC) were synthesized and characterized. Viscosity of polymers in presence of various concentrations of S-amino acids was monitored. Mucoadhesive properties were evaluated. FT-IR characterization confirmed the covalent attachment of NAC-MNA and NAC-NAC. Attached sulfhydryl groups were found in the range of 550 μmol/g. In the presence of amino acids bearing a free thiol group viscosity of both polymers increased. This increase in viscosity depended on the amount of added free thiols. Maximum force required to detach CS-NAC-MNA and CS-NAC-NAC from porcine intestinal mucosa was 1.4- and 2.7-fold higher than that required for chitosan, respectively. CS-NAC-MNA adhered up to 3 h, whereas CS-NAC-NAC adhered even for 8 h on this mucosa. Accordingly, the Cys-Cys substructure could be identified as highly potent ligand for the design of mucoadhesive polymers.

Chitosan-Functionalized Mg0.5Co0.5Fe2O4 Magnetic Nanoparticles Enhance Delivery of 5-Fluorouracil In Vitro

Magnetic nanoparticles (MNPs) have been widely investigated as a strategy to improve the delivery efficiency of therapeutic and diagnostic agents. Substituted iron oxides or ferrite nanoparticles (NPs) such as CoFe2O4 represent an interesting and novel class of MNPs, although they are under-researched in the field of biomedicine. In this study, chitosan-functionalized Mg0.5Co0.5Fe2O4 NPs were loaded with the anti-cancer 5-fluorouracil (5-FU) drug to yield CS-Mg0.5Co0.5Fe2O4-5FU. Transmission electron microscopy (TEM), Fourier Transform infra-red (FTIR) spectroscopy and nanoparticle tracking analysis (NTA) were employed to determine the physiochemical properties of the NPs. Physico-chemical characterizations confirmed spherical NPs with particle sizes of approximately 20.39 nm. Improved colloidal stability was observed, as determined by a zeta potential of approximately −20 mV for the drug-loaded CS-Mg0.5Co0.5Fe2O4 NPs. Drug encapsulation efficiencies of >60% were attained, showing a pH-dependent release of 5-FU. Cell viabilities investigated using the 3-[(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) and sulforodhamine B (SRB) assays in human embryonic kidney (HEK293), human breast adenocarcinoma (MCF-7) and human cervical cancer (HeLa) cells showed that these drug-loaded NPs exhibited more targeted tumor-specific cytotoxicities compared to free drugs. CS-Mg0.5Co0.5Fe2O4-5-FU NPs displayed significant targeted delivery potential to the investigated cancer cell lines. Conclusively, these results suggest that the CS-Mg0.5Co0.5Fe2O4-5-FU NPs are promising therapeutic delivery systems in anti-cancer treatment.

Gentamicin decorated phosphatidylcholine-chitosan nanoparticles against biofilms and intracellular bacteria

Biofilms and intracellular bacteria often cause a series of overwhelming public health issues due to their strong drug resistance. Hence, chitosan nanoparticles (CS NPs), phosphatidylcholine and gentamicin were used to synthesize a novel nanodrug delivery system (GPC NPs). Dynamic light scattering (DLS) demonstrated that the surface zeta-potential of GPC NPs was -19.5 mV. The morphology of GPC NPs was observed by scanning electron microscopy (SEM). The gentamicin adsorption and release behaviors of GPC NPs were also investigated. The GPC NPs could effectively damage and remove the biofilm formed by pathogens through permeation of the antibiotic into the biofilm. In addition, the nanoparticles were readily engulfed by macrophages which facilitated the killing of intracellular bacteria and had neglectable cytotoxicity. Our study indicated that GPC NPs could be used as a promising nanoantibacterial agent against biofilms and intracellular bacteria.

Antibacterial effect of chitosan and its derivative on Enterococcus faecalis associated with endodontic infection

Chitosan and its derivatives have been increasingly used for bacteriostasis. To date, the effect of chitosan and N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) on Enterococcus faecalis (E. faecalis) associated with endodontic infection has remained to be determined. Chitosan and HTCC were serially diluted with double-distilled water (DDW) or PBS at concentrations of 20-2,500 µg/ml. Various strains of E. faecalis (American Type Tissue Collection no. 29212, as well as isolated strains P25RC and P52Sa) in plankton were adjusted to an optical density at 600 nm of 0.10 and treated with chitosan or HTCC. A colony-forming unit assay was used to determine the concentration of residual bacteria after treatment. Furthermore, E. faecalis biofilms were cultured on coverslips and treated with chitosan or HTCC. The coverslips were rinsed, stained using Live/dead^® BacLight™ bacterial viability kit and observed under an inverted fluorescence microscope. In addition, biofilms on dentine blocks were prepared and observed under a scanning electron microscope. MC3T3-E1 pre-osteoblasts were seeded on 96-well plates and treated with chitosan or HTCC at various concentrations. The cytotoxicity of chitosan and HTCC on MC3T3-E1 pre-osteoblasts was detected using a Cell Counting Kit-8 assay after 24, 48 and 72 h of treatment. The results revealed that the final minimum bactericidal concentrations (MBC) of chitosan and HTCC dissolved in DDW were 70 and 140 µg/ml, respectively. Chitosan and HTCC in DDW exerted a significantly greater antibacterial effect as compared with that in PBS (P<0.05). At the MBC, chitosan and HTCC in DDW, but particularly chitosan, had a significant antibacterial effect on E. faecalis biofilm. Chitosan exhibited no cytotoxicity to MC3T3-E1 pre-osteoblasts at a concentration of <625 µg/ml, while HTCC inhibited the proliferation of the cells in the concentration range of 39-10,000 µg/ml. In conclusion, chitosan and HTCC exhibited prominent antibacterial properties on E. faecalis in the planktonic state and as a biofilm via charge interaction, indicating their potential for application in root canal disinfection and fillings.

Recent Advancements in Using Polymers for Intestinal Mucoadhesion and Mucopenetration

Oral administration of actives is the most desired form of delivery, but the formulations need to overcome a variety of barriers including the intestinal mucus. This feature article summarizes the developments from the past 2-3 years in this context focusing on polymer-based formulations. The progress in assembling mucopenetrating nanoparticles is outlined considering coatings using noninteracting polymers as well as virus-like particles and charge-shifting particles. Next, polymers and their modification to enhance mucoadhesion are discussed, followed by providing examples of double-encapsulation systems that aim to combine mucopenetration with mucoadhesion in the same formulation. Finally, a short outlook is provided highlighting a few of the most pressing challenges to address.

Micro and nanoscale technologies in oral drug delivery

Oral administration is a pillar of the pharmaceutical industry and yet it remains challenging to administer hydrophilic therapeutics by the oral route. Smart and controlled oral drug delivery could bypass the physiological barriers that limit the oral delivery of these therapeutics. Micro- and nanoscale technologies, with an unprecedented ability to create, control, and measure micro- or nanoenvironments, have found tremendous applications in biology and medicine. In particular, significant advances have been made in using these technologies for oral drug delivery. In this review, we briefly describe biological barriers to oral drug delivery and micro and nanoscale fabrication technologies. Micro and nanoscale drug carriers fabricated using these technologies, including bioadhesives, microparticles, micropatches, and nanoparticles, are described. Other applications of micro and nanoscale technologies are discussed, including fabrication of devices and tissue engineering models to precisely control or assess oral drug delivery in vivo and in vitro, respectively. Strategies to advance translation of micro and nanotechnologies into clinical trials for oral drug delivery are mentioned. Finally, challenges and future prospects on further integration of micro and nanoscale technologies with oral drug delivery systems are highlighted.

Chitosan is a potential inhibitor of ovarian cancer: Molecular aspects

Although ovarian cancer has a lower prevalence than breast cancer, its mortality rate is three times higher, which is reported to increase in the coming years. As the early stages of ovarian cancer do not have any obvious symptoms, in most of the cases, this cancer is diagnosed at advanced stages with a poor prognosis. Moreover, in many patients who are diagnosed with advanced stage, relapse of the disease and drug resistance are observed. Over the past years, these women have been treated with chemotherapy and cytoreductive surgeries. However, the chemotherapy could affect the healthy tissues in addition to the malignancies. Therefore, discovering new diagnostic and therapeutic options seems to be a crucial need. Unlike the common invasive and/or nonspecific treatments, nanomedicine is trying to find a new way for cancer imaging, diagnosis, and drug delivery method. Nanoparticles (NPs), which has recently drawn attention, can be used in order to reduce the toxicity and frequent dosing of drugs, tumor-specific delivery, and early diagnosis for malignancies. Chitosan as an NP and product of chitin deacetylation has multiple characteristics, including biocompatibility, biodegradability, and safety. In this review, we cover the studies concerned with the role of chitosan in finding solutions to overcome the problems faced in ovarian cancer treatments. Furthermore, we highlight how chitosan is being used in delivering chemotherapy drugs, gene therapy, and imaging methods for both detection and image-guided therapies.

Encapsulation of Plant-derived Bioactive Ingredients through Electrospraying for Nutraceuticals and Functional Foods Applications

The electrospraying technique, which consists of electrohydrodynamic atomization of polymeric fluids, can be used to generate dry nano- and microparticles by subjecting a polymer solution, suspension or melt to a high voltage (typically in the range of 7-20 kV) electric field. This potential can be exploited for developing nano- and microencapsulation structures under mild temperature conditions. Thus, it constitutes a promising alternative to conventional microencapsulation techniques for sensitive ingredients, like most plant-derived bioactive compounds, especially for their application in the food sector. Given the importance of plants as one of the major sources of dietary bioactive compounds, significant attention has been recently paid to research the encapsulation of phytochemicals through novel techniques such as electrospraying, aiming to provide new tools for the development of innovative functional food products and nutraceuticals. In this review, the latest advances in the application of electrospraying for nano- and microencapsulation of phytochemicals are discussed, with a focus on their potential use in the food sector.

Chitin and Chitosans: Characteristics, Eco-Friendly Processes, and Applications in Cosmetic Science

Huge amounts of chitin and chitosans can be found in the biosphere as important constituents of the exoskeleton of many organisms and as waste by worldwide seafood companies. Presently, politicians, environmentalists, and industrialists encourage the use of these marine polysaccharides as a renewable source developed by alternative eco-friendly processes, especially in the production of regular cosmetics. The aim of this review is to outline the physicochemical and biological properties and the different bioextraction methods of chitin and chitosan sources, focusing on enzymatic deproteinization, bacteria fermentation, and enzymatic deacetylation methods. Thanks to their biodegradability, non-toxicity, biocompatibility, and bioactivity, the applications of these marine polymers are widely used in the contemporary manufacturing of biomedical and pharmaceutical products. In the end, advanced cosmetics based on chitin and chitosans are presented, analyzing different therapeutic aspects regarding skin, hair, nail, and oral care. The innovative formulations described can be considered excellent candidates for the prevention and treatment of several diseases associated with different body anatomical sectors.

Electrospinning and electrospraying technologies for food applications

Electrospinning and electrospraying are versatile techniques for the production of nano- to micro-scale fibers and particles. Over the past 2 decades, significant progresses have been made to advance the fundamental understandings of these electrohydrodynamic processes. Researchers have investigated different polymeric and non-polymeric substrates for producing submicron electrospun/electrosprayed materials of unique morphologies and physicochemical properties. This chapter provides an overview on the basic principles of electrospinning and electrospraying, highlighting the effects of key processing and solution parameters. Electrohydrodynamic phenomena of edible substrates, including polysaccharides (xanthan, alginate, starch, cyclodextrin, pullulan, dextran, modified celluloses, and chitosan), proteins (zein, what gluten, whey protein, soy protein, gelatin, etc.), and phospholipids are reviewed. Selected examples are presented on how ultrafine fibers and particles derived from these substrates are being exploited for food and nutraceutical applications. Finally, the challenges and opportunities of the electrostatic methods are discussed.

Challenges and Recent Progress in Oral Drug Delivery Systems for Biopharmaceuticals

Routes of drug administration and the corresponding physicochemical characteristics of a given route play significant roles in therapeutic efficacy and short term/long term biological effects. Each delivery method has favorable aspects and limitations, each requiring a specific delivery vehicles design. Among various routes, oral delivery has been recognized as the most attractive method, mainly due to its potential for solid formulations with long shelf life, sustained delivery, ease of administration and intensified immune response. At the same time, a few challenges exist in oral delivery, which have been the main research focus in the field in the past few years. The present work concisely reviews different administration routes as well as the advantages and disadvantages of each method, highlighting why oral delivery is currently the most promising approach. Subsequently, the present work discusses the main obstacles for oral systems and explains the most recent solutions proposed to deal with each issue.

Pharmaceutical applications of chitosan

Chitosan (CS) is a linear polysaccharide which is achieved by deacetylation of chitin, which is the second most plentiful compound in nature, after cellulose. It is a linear copolymer of β-(1 → 4)-linked 2-acetamido-2-deoxy-β-d-glucopyranose and 2-amino-2-deoxy-β-d-glucopyranose. It has appreciated properties such as biocompatibility, biodegradability, hydrophilicity, nontoxicity, high bioavailability, simplicity of modification, favorable permselectivity of water, outstanding chemical resistance, capability to form films, gels, nanoparticles, microparticles and beads as well as affinity to metals, proteins and dyes. Also, the biodegradable CS is broken down in the human body to safe compounds (amino sugars) which are easily absorbed. At present, CS and its derivatives are broadly investigated in numerous pharmaceutical and medical applications including drug/gene delivery, wound dressings, implants, contact lenses, tissue engineering and cell encapsulation. Besides, CS has several OH and NH₂ functional groups which allow protein binding. CS with a deacetylation degree of ~50% is soluble in aqueous acidic environment. While CS is dissolved in acidic medium, its amino groups in the polymeric chains are protonated and it becomes cationic which allows its strong interaction with different kinds of molecules. It is believed that this positive charge is responsible for the antimicrobial activity of CS through the interaction with the negatively charged cell membranes of microorganisms. This review presents properties and numerous applications of chitosan-based compounds in drug delivery, gene delivery, cell encapsulation, protein binding, tissue engineering, preparation of implants and contact lenses, wound healing, bioimaging, antimicrobial food additives, antibacterial food packaging materials and antibacterial textiles. Moreover, some recent molecular dynamics simulations accomplished on the pharmaceutical applications of chitosan were presented.

Preparation and Characterization of an Oral Vaccine Formulation Using Electrosprayed Chitosan Microparticles

Chitosan particles loaded with the antigen ovalbumin (OVA) and the adjuvant Quil-A were produced by electrospray, using mixtures of water/ethanol/acetic acid as a solvent. Three different chitosans designed as HMC⁺70, HMC⁺85, and HMC⁺90 (called as 705010, 855010, and 905010) were tested and its efficacy to be used in oral vaccine delivery applications was investigated. The morphology, size, and zeta potential of the produced particles were investigated, together with the encapsulation efficiency and release of OVA from the three chitosan formulations. Moreover, the mucoadhesion and cytotoxicity of the chitosan microparticles was examined. All the three formulations with OVA and Quil-A were in the micrometer size range and had a positive zeta potential between 46 and 75 mV. Furthermore, all the three formulations displayed encapsulation efficiencies above 80% and the release of OVA over a period of 80 h was observed to be between 38 and 47%. None of the developed formulations exhibited high mucoadhesive properties, either cytotoxicity. The formulation prepared with HMC⁺70, OVA, and Quil-A had the highest stability within 2 h in buffer solution, as measured by dynamic light scattering. The electrosprayed formulation consisting of HMC⁺70 with OVA and Quil-A showed to be the most promising as an oral vaccine system.