Chitosan nanoparticles: Preparation, size evolution and stability

Building and behavior of a pH-stimuli responsive chitosan nanoparticles loaded with folic acid conjugated gemcitabine silver colloids in MDA-MB-453 metastatic breast cancer cell line and pharmacokinetics in rats

The pH-stimuli release behavior of nanoformulations may enhance the success rate of chemotherapeutic drugs in cancers by site-specific delivery of drugs to cancer tissues. The aim of the present study was to prepare chitosan (CS) nanoparticles (NPs) with previously synthesized folic acid (FA) capped silver nanoparticles (AgNPs) loaded with the anti-cancer drug gemcitabine (GEM) (FA-GEM-AgNPs). The CS-FA-GEM-AgNPs (CS-NPs) were characterized with dynamic light scattering (DLS), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDAX), selected area electron diffraction (SAED), and differential scanning calorimetric (DSC) analyses. The in-vitro drug release of GEM was evaluated in media of different pH. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was carried out to determine the cytotoxic effects of the prepared nanoformulations in media with various pH. The time- and pH-dependent apoptotic cell death induced by CS-NPs with MDA-MB-453 human breast cancer cell line was observed using acridine orange (AO)/ethidium bromide (EtBr) staining. The pharmacokinetic parameters were studied with high-performance liquid chromatography (HPLC) and atomic absorption spectroscopy (AAS). Two batches of CS-NPs formulations were prepared, one with AgNPs of particle size 143 nm and the other with 244 nm. The particle size for CS-NPs-I (FA-GEM-AgNPs-143 nm) and CS-NPs-II (FA-GEM-AgNPs-244 nm) was found to be 425 and 545 nm, respectively. The zeta potential was found to be 36.1 and 37.5 mV for CS-NPs-I and CS-NPs-II, respectively. CS-NPs-I and CS-NPs-II showed a polydispersity index (PDI) of 0.240 and 0.261, respectively. A TEM study confirmed the spherical nature of the NPs. The nanoformulations exerted pH-dependant effect against MDA-MB-453 cells with relatively higher cytotoxicity at the lower pH than at higher pH levels. The pharmacokinetic profile and tissue distribution of CS-NPs in rats exerted drug release in a pH-dependent manner with enhanced excretion of Ag⁺. An optimized nanoformulation for pH-stimuli responsive release of GEM was successfully developed for future therapeutic exploration.

Chitosan nanoparticles as a promising tool in nanomedicine with particular emphasis on oncological treatment

The study describes the current state of knowledge on nanotechnology and its utilization in medicine. The focus in this manuscript was on the properties, usage safety, and potentially valuable applications of chitosan-based nanomaterials. Chitosan nanoparticles have high importance in nanomedicine, biomedical engineering, discovery and development of new drugs. The manuscript reviewed the new studies regarding the use of chitosan-based nanoparticles for creating new release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity of drugs. Nowadays, effective cancer treatment is a global problem, and recent advances in nanomedicine are of great importance. Special attention was put on the application of chitosan nanoparticles in developing new system for anticancer drug delivery. Pre-clinical and clinical studies support the use of chitosan-based nanoparticles in nanomedicine. This manuscript overviews the last progresses regarding the utilization, stability, and bioavailability of drug nanoencapsulation with chitosan and their safety.

A comprehensive survey upon diverse and prolific applications of chitosan-based catalytic systems in one-pot multi-component synthesis of heterocyclic rings

Heterocyclic compounds are among the most prestigious and valuable chemical molecules with diverse and magnificent applications in various sciences. Due to the remarkable and numerous properties of the heterocyclic frameworks, the development of efficient and convenient synthetic methods for the preparation of such outstanding compounds is of great importance. Undoubtedly, catalysis has a conspicuous role in modern chemical synthesis and green chemistry. Therefore, when designing a chemical reaction, choosing and or preparing powerful and environmentally benign simple catalysts or complicated catalytic systems for an acceleration of the chemical reaction is a pivotal part of work for synthetic chemists. Chitosan, as a biocompatible and biodegradable pseudo-natural polysaccharide is one of the excellent choices for the preparation of suitable catalytic systems due to its unique properties. In this review paper, every effort has been made to cover all research articles in the field of one-pot synthesis of heterocyclic frameworks in the presence of chitosan-based catalytic systems, which were published roughly by the first quarter of 2020. It is hoped that this review paper can be a little help to synthetic scientists, methodologists, and catalyst designers, both on the laboratory and industrial scales.

Mucoadhesive Low Molecular Chitosan Complexes to Protect rHuKGF from Proteolysis: In-vitro Characterization and FHs 74 Int Cell Proliferation Studies

BACKGROUND

Recombinant Keratinocyte Growth Factor (rHuKGF) is a therapeutic protein used widely in oral mucositis after chemotherapy in various cancers, stimulating lung morphogenesis and gastrointestinal tract cell proliferation. In this research study, chitosan-rHuKGF polymeric complex was implemented to improve the stability of rHuKGF and used as rejuvenation therapy for the treatment of oral mucositis in cancer patients.

OBJECTIVE

Complexation of rHuKGF with mucoadhesive low molecular weight chitosan to protect rHuKGF from proteolysis and investigate the effect of chitosan-rHuKGF complex on the proliferation rate of FHs 74 Int cells.

METHODS

The interaction between chitosan and rHuKGF was studied by molecular docking. Malvern ZetaSizer Nano Zs and Fourier-Transform Infrared spectroscopy (FTIR) tests were carried out to characterize the chitosan-rHuKGF complex. In addition, SDS-PAGE was performed to investigate the interaction between chitosan-rHuKGF complex and pepsin. The effect of chitosan-rHuKGF complex on the proliferation rate of FHs 74 Int cells was studied by MTT assay.

RESULTS

Chitosan-rHuKGF complex was formed through the hydrogen bonding proven by the docking studies. A stable chitosan-rHuKGF complex was formed at pH 4.5 and was protected from proteolysis and assessed by SDS PAGE. According to the MTT assay results, chitosan-rHuKGF complex increased the cell proliferation rate of FHs 74 Int cells.

CONCLUSION

The developed complex improved the stability and the biological function of rHuKGF.

Synthesis and Characterization of Chitosan Particles Loaded with Antioxidants Extracted from Chia (Salvia hispanica L.) Seeds

Chia (Salvia hispanica L.) seeds contain antioxidants with great benefits for health and are widely used in the food industry. Antioxidants can be degraded by environmental factors, decreasing their biological activity. Their encapsulation in chitosan (CH) particles represents an alternative to protect them and increases their application. The encapsulation efficiency (%EE) of the antioxidants in the CH particles depends on the synthesis conditions. In this study, two methods for encapsulation of chia extract in chitosan particles were evaluated: method A, 0.05% CH in 1% acetic acid was mixed with 0.07% of tripolyphosphate (TPP) and method B, 0.3% CH in 2% acetic acid was mixed with 1% TPP. The results showed that the %EE decreased with the concentration of the extract, and the FTIR analysis suggested that the compounds of the extract were adsorbed on the surface of the particles. Dynamic light scattering and zeta potential analysis showed that the particles of method A are unstable and with a tendency to agglomerate, and the particles of method B are stable. The highest %EE was obtained with 0.2 mg·mL⁻¹ (method A) and 1.0 mg·mL⁻¹ (method B) of the extract. The higher loading capacity (%LC) (16–72%) was exhibited by the particles of method A. The best particle yield (62–69%) was observed for method B. The particles with the extract adsorbed showed antioxidant activity (5–60%) at 25°C; however, in the particles with the extract encapsulated, the activity increased after subjecting to acidic conditions at 40°C due to the breakdown of the particles. The results obtained will allow choosing the appropriate conditions for the synthesis of chitosan particles loaded with chia extracts with specific characteristics (%EE, %LC, size, and type) according to their future applications. The particles could be used in food and pharmaceutical industries and even in edible films for food packaging.

The Potential Role of Polyelectrolyte Complex Nanoparticles Based on Cashew Gum, Tripolyphosphate and Chitosan for the Loading of Insulin

Polyelectrolytic complexation has stood out due to its application in the development of drug delivery systems using biopolymers as raw materials. The formation of complexes between cashew gum and chitosan can be intermediated by cross-links, mediated by the action of the sodium tripolyphosphate crosslinking agent. These polymers have been used in the nanotechnological development of formulations to protect peptide drugs, such as insulin, allowing their oral administration. In this work, we describe the development of polyelectrolytic complexes from cashew gum and chitosan as biopolymers for oral administration of insulin. The obtained complexes showed a mean particle size of 234 nm and polydispersity index of 0.2. The complexes were 234 nm in size, PDI 0.2, zeta potential −4.5 mV and 22% trapping. The obtained complexes demonstrated considerable and promising characteristics for use as oral insulin delivery systems.

Chitosan-Based Nanoparticles of Targeted Drug Delivery System in Breast Cancer Treatment

Breast cancer remains one of the world's most dangerous diseases because of the difficulty of finding cost-effective and specific targets for effective and efficient treatment methods. The biodegradability and biocompatibility properties of chitosan-based nanoparticles (ChNPs) have good prospects for targeted drug delivery systems. ChNPs can transfer various antitumor drugs to targeted sites via passive and active targeting pathways. The modification of ChNPs has attracted the researcher to the loading of drugs to targeted cancer cells. The objective of our review was to summarize and discuss the modification in ChNPs in delivering anticancer drugs against breast cancer cells from published papers recorded in Scopus, PubMed, and Google Scholar. In order to improve cellular uptake, drug accumulation, cytotoxicity, and selectivity, we examined different kinds of modification of ChNPs. Notably, these forms of ChNPs use the characteristics of the enhanced permeability and retention (EPR) effect as a proper parameter and different biological ligands, such as proteins, peptides, monoclonal antibodies, and small particles. In addition, as a targeted delivery system, ChNPs provided and significantly improved the delivery of drugs into specific breast cancer cells (MDA-MB-231, 4T1 cells, SK-BR-3, MCF-7, T47D). In conclusion, a promising technique is presented for increasing the efficacy, selectivity, and effectiveness of candidate drug carriers in the treatment of breast cancer.

Lignin, lipid, protein, hyaluronic acid, starch, cellulose, gum, pectin, alginate and chitosan-based nanomaterials for cancer nanotherapy: Challenges and opportunities

Although nanotechnology-driven drug delivery systems are relatively new, they are rapidly evolving since the nanomaterials are deployed as effective means of diagnosis and delivery of assorted therapeutic agents to targeted intracellular sites in a controlled release manner. Nanomedicine and nanoparticulate drug delivery systems are rapidly developing as they play crucial roles in the development of therapeutic strategies for various types of cancer and malignancy. Nevertheless, high costs, associated toxicity and production of complexities are some of the critical barriers for their applications. Green nanomedicines have continually been improved as one of the viable approaches towards tumor drug delivery, thus making a notable impact on which considerably affect cancer treatment. In this regard, the utilization of natural and renewable feedstocks as a starting point for the fabrication of nanosystems can considerably contribute to the development of green nanomedicines. Nanostructures and biopolymers derived from natural and biorenewable resources such as proteins, lipids, lignin, hyaluronic acid, starch, cellulose, gum, pectin, alginate, and chitosan play vital roles in the development of cancer nanotherapy, imaging and management. This review uncovers recent investigations on diverse nanoarchitectures fabricated from natural and renewable feedstocks for the controlled/sustained and targeted drug/gene delivery systems against cancers including an outlook on some of the scientific challenges and opportunities in this field. Various important natural biopolymers and nanomaterials for cancer nanotherapy are covered and the scientific challenges and opportunities in this field are reviewed.

Tumor-mediated shape-transformable nanogels with pH/redox/enzymatic-sensitivity for anticancer therapy

Lack of sufficient tumor penetration of the current nanomedicines is a major reason limiting their clinical success in cancer therapy. In this work, we aimed at the development of a novel biodegradable nanoplatform for the selective and controlled delivery of anticancer agents, with improved tumor permeability and the ability to release ultrasmall nanovesicles in the tumor microenvironment. To this end, positively charged nanogels were obtained through the double-crosslinking of chitosan with an ionic physical gelator and a disulfide-containing chemical crosslinker. After conjugation to an anionic oligomer, the cationic nanogels were transformed into negatively charged nanocarriers (CTCP), enabling effective encapsulation of the cationic anticancer agent doxorubicin (DOX) to generate a biodegradable nanomedicine (DOX@CTCP). DOX@CTCP could maintain sustained DOX release and decreased DOX toxicity. Upon arrival at the tumor tissue, the reductive and lysozyme-high microenvironment drives the cleavage of the nanomedicine to release DOX-carrying nanoblocks of smaller size, which together with their acidic-protonable feature achieves an effective therapeutic delivery into cancer cells. The nanomedicine described here showed excellent biocompatibility/biosafety and enhanced in vivo antitumor efficacy.

Mucoadhesive Formulation Designs for Oral Controlled Drug Release at the Colon

Mucoadhesive formulations have been demonstrated to result in efficient drug delivery systems with advantages over existing systems such as increased local retention and sustained drug release via adhesiveness to mucosal tissues. The controlled release of colon-targeted, orally administered drugs has recently attracted a number of studies investigating mucoadhesive systems. Consequently, substantial designs, from mucoadhesive cores to shells of particles, have been studied with promising applications. This review will provide an overview of specific strategies for developing mucoadhesive systems for colon-targeted oral delivery with controlled drug release, including mucoadhesive matrices, cross-linked mucoadhesive microparticles, coatings and mucoadhesive nanoparticles. The understanding of the basic principle of these designs and advanced formulations throughout will lead to the development of products with efficient drug delivery at the colon for therapies for different diseases.

Cashew Gum Polysaccharide Nanoparticles Grafted with Polypropylene Glycol as Carriers for Diclofenac Sodium

This investigation focuses on the development and optimization of cashew gum polysaccharide (CGP) nanoparticles grafted with polypropylene glycol (PPG) as carriers for diclofenac sodium. The optimization of parameters affecting nanoparticles formulation was performed using a central composite rotatable design (CCRD). It was demonstrated that the best formulation was achieved when 10 mg of CGP was mixed with 10 μL of PPG and homogenized at 22,000 rpm for 15 min. The physicochemical characterization evidenced that diclofenac was efficiently entrapped, as increases in the thermal stability of the drug were observed. The CGP-PPG@diclofenac nanoparticles showed a globular shape, with smooth surfaces, a hydrodynamic diameter around 275 nm, a polydispersity index (PDI) of 0.342, and a zeta potential of -5.98 mV. The kinetic studies evidenced that diclofenac release followed an anomalous transport mechanism, with a sustained release up to 68 h. These results indicated that CGP-PPG nanoparticles are an effective material for the loading/release of drugs with similar structures to diclofenac sodium.

Contribution of Attenuation of TNF-α and NF-κB in the Anti-Epileptic, Anti-Apoptotic and Neuroprotective Potential of Rosa webbiana Fruit and Its Chitosan Encapsulation

Rosa webbiana L. (Rosaceae) is one of the least reported and most understudied members of this family. It is native to the Himalayan regions of Pakistan and Nepal. The anti-convulsant effect of n-hexane extract of fruit of Rosa webbiana was investigated in a pentylenetetrazole (PTZ)-induced animal model of epilepsy. Male Sprague-Dawley rats were divided into six groups (n = 7) including control, PTZ (40 mg/kg), diazepam (4 mg/kg) and n-hexane extract (at 50, 150 and 300 mg/kg). Convulsive behavior was observed and resultant seizures were scored, animals sacrificed and their brains preserved. Chitosan nanoparticles were prepared using the ionic gelation method and characterized by UV-analysis, zeta potential and Fourier transform infrared spectroscopy (FTIR). The effects of all the treatments on the expression of phosphorylated cytokine tumor necrosis factor α (p-TNF-α) and phosphorylated transcription factor nuclear factor kappa B (p-NF-κB) expression in the cortex and hippocampus of the brains of treated rats were studied through enzyme linked immunosorbent assay (ELISA) and morphological differences and surviving neuronal number were recorded through hematoxylene and eosin (H&E) staining. Significant changes in seizures score and survival rate of rats were observed. Downregulation of neuro-inflammation, p-TNF-α and p-NF-κB was evident. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of this fraction showed multiple constituents of interest, including esters, alkanes and amines.

Immunostimulatory effect of chitosan and quaternary chitosan: A review of potential vaccine adjuvants

Vaccines have always been the most effective preventive treatment. Advancements in the field of vaccine is inseparable from adjuvants. Adjuvants are substances added to vaccines to enhance immunogenicity and induce a stronger immune response. Chitosan fascinated considerable attention as vaccine adjuvant due to its unique physicochemical and biological properties. Many studies have shown that chitosan and its derivatives can effectively activate antigen-presenting cells and induce cytokine stimulation to produce an effective immune response and promote the balance of Th1/Th2 response. Among many derivatives, the quaternized chitosan performs better. This review presents the main factors affecting the adjuvant performance of chitosan and quaternized chitosan firstly. Then, we introduced not only the immune response they may cause, but also their metabolic research in detail. Furthermore, their future prospects are forecasted. Overall, chitosan and quaternized chitosan are both promising adjuvant materials, and quaternized chitosan shows greater potential.

Monitoring the infection process of Rhizopus stolonifer on strawberry fruit during storage using films based on chitosan/polyvinyl alcohol/polyvinylpyrrolidone and plant extracts

Different formulations based on nanoparticles of chitosan-plant extracts were evaluated to detect the infection process from the earliest stage of the fungus Rhizopus stolonifer on strawberry fruit during storage. Chitosan/polyvinyl alcohol (Ch/PVA) and chitosan/polyvinylpyrrolidone (Ch/PVP) films enriched with nanoparticles (NPs) of chitosan blended with plant extracts were prepared. They were placed inside a plastic package containing inoculated fruits and stored at 25 °C for 72 h. The thickness values of the films were in the range of 0.10 to 0.25 mm. All samples showed a maximum absorbance peak of about 300-320 nm; however, the Ch/PVP films enriched with NPs of chitosan and 10% of radish extract had an evident decrease in the optical absorbance as the fungal infection progressed. Additionally, as observed by scanning electron microscopy, the cross-section and surface morphology of films were not modified during storage, and the growth of R. stolonifer was evident after 48 h. Therefore, the Ch/PVP films enriched with chitosan NPs blended with 10% radish extract could be a reliable indicator of this fungus's growth.

Chitosan Nanoparticles Loaded with N-Acetyl Cysteine to Mitigate Ozone and Other Possible Oxidative Stresses in Durum Wheat

Modern durum wheat cultivars are more prone to ozone stress because of their high photosynthetic efficiency and leaf gas exchanges that cause a greater pollutant uptake. This, in turn, generates an increased reactive oxygen species (ROS) production that is a challenge to control by the antioxidant system of the plant, therefore affecting final yield, with a reduction up to 25%. With the aim of mitigating oxidative stress in wheat, we used chitosan nanoparticles (CHT-NPs) either unloaded or loaded with the antioxidant compound N-acetyl cysteine (NAC), on plants grown either in a greenhouse or in an open field. NAC-loaded NPs were prepared by adding 0.5 mg/mL NAC to the CHT solution before ionotropic gelation with tripolyphosphate (TTP). Greenhouse experiments evidenced that CHT-NPs and CHT-NPs-NAC were able to increase the level of the leaf antioxidant pool, particularly ascorbic acid (AsA) content. However, the results of field trials, while confirming the increase in the AsA level, at least in the first phenological stages, were less conclusive. The presence of NAC did not appear to significantly affect the leaf antioxidant pool, although the grain yield was slightly higher in NAC-treated parcels. Furthermore, both NAC-loaded and -unloaded CHT-NPs partially reduced the symptom severity and increased the weight of 1000 seeds, thus showing a moderate mitigation of ozone injury.

Iron nanoparticles as novel vaccine adjuvants

The poor immunogenicity of peptide vaccines compared to conventional ones re usually improved by applying different adjuvants. As chemical or biological substances, adjuvants are added to vaccines to enhance and prolong the immune response. According to considerable investigations over the recent years in the context of finding new adjuvants, a handful of vaccine adjuvants have been licensed for human use. Recently, engineered nanoparticles (NPs) have been introduced as novel alternatives to traditional vaccine adjuvant. Metallic nanoparticles (MeNPs) are among the most promising NPs used for vaccine adjuvant as well as the delivery system that can improve immune responses against pathogens. Iron NPs, as an important class of MeNPs, have gained increasing attention as novel vaccine adjuvants. These particles have shown acceptable results in preclinical studies. Hence, understanding the physicochemical properties of iron NPs, including size, surface properties, charge and route of administration, is of substantial importance. The aim of this review is to provide an overview of the immunomodulatory effects of iron NPs as novel adjuvants. Furthermore, physicochemical properties of these NPs were also discussed.

Protective Action of Jania rubens Nanoencapsulated Algal Extract in Controlling Vegetable Oils' Rancidity

The development of natural antioxidants that can mitigate oil oxidation is on the rise. Several antioxidants have been developed from natural terrestrial plants, with less emphasis on marine algae. Rancidity is a major degradative reaction limiting the shelf-life and deteriorating the quality of vegetable oils. The goal of this study was to evaluate the ability of the Jania rubens' (J. rubens) seaweed extract encapsulated by chitosan/tripolyphosphate in retarding lipids' oxidation in vegetable oils. To improve the J. rubens efficacy, the extract was nanoencapsulated using the ionic gelation method. A Box-Behnken design was applied for the optimization of the formulation variables (chitosan/tripolyphosphate amounts, homogenization time, and homogenization speed). The optimum nanoformulation was characterized by transmission electron microscopy. It had a particle size of 161 nm, zeta potential of 31.2 mV, polydispersity index of 0.211, and entrapment efficiency of 99.7%. The ability of the optimum formula to extend the shelf-life of vegetable oils was based on peroxide value and thiobarbituric acid assays. In addition, headspace solid-phase microextraction was applied to detect the oils' volatiles as secondary markers of rancidity. The results revealed that the nanoencapsulated algal extract considerably reduced the rate of oils' oxidation and that its activity was comparable to that of a widely used synthetic antioxidant.

Bioengineered ethosomes encapsulating AgNPs and Tasar silk sericin proteins for non melanoma skin carcinoma (NMSC) as an alternative therapeutics

Rising cases of Non melanoma skin carcinoma (NMSC) and escalating levels of ultraviolet radiations have underlined a profound correlation with the elevating levels of environmental detoriation and increasing health issues. However, the availability of therapeutics has not aided in controlling the recurrence rates of skin carcinoma. Frequent administration of therapeutics with higher chances of facial deformity escalates the patient's treatment expenses. Thus, this study initiates a low cost effective and biodegradable therapy by exploring four formulations with combinations of silver nanoparticles (AgNPs), sericin (isolated from cocoons of Antherea mylitta) and chitosan. Subsequently, various ethosomal formulations were evaluated as a platform for transdermal delivery vehicle for efficient skin intervention therapeutics. Characterization using UV visible spectroscopy, Dynamic light scattering, Fourier Infrared spectroscopy, X-ray dispersion, Transmission electron microscopy, Fluorescence assisted cell sorting and in vitro studies were done and it was inferenced that equal combination of AgNPs and sericin facilitated to combat the morphological and cellular deformation of the epidermoid A431skin carcinoma cells. The overproduction of superoxide (O^2.) and nitric oxide (NO) radicals consequently depolarized the mitochondrial membrane potential triggering apoptosis and necrosis. The in vivo experiments exhibited the stimulation of IgM secretion with T cell-mediated immune response. Therefore, this study proposes a novel approach for treatment of NMSC using biocompatible formulations delivered through ethosomes.

Chitosan nanoparticles for enhancing drugs and cosmetic components penetration through the skin

Chitosan nanoparticles (CT NPs) have attractive biomedical applications due to their unique properties. This present research aimed at development of chitosan nanoparticles to be used as skin delivery systems for cosmetic components and drugs and to track their penetration behaviour through pig skin. CT NPs were prepared by ionic gelation technique using sodium tripolyphosphate (TPP) and Acacia as crosslinkers. The particle sizes of NPs appeared to be dependent on the molecular weight of chitosan and concentration of both chitosan and crosslinkers. CT NPs were positively charged as demonstrated by their Zeta potential values. The formation of the nanoparticles was confirmed by FTIR and DSC. Both SEM and TEM micrographs showed that both CT-Acacia and CT:TPP NPs were smooth, spherical in shape and are distributed uniformly with a size range of 200nm to 300 nm. The CT:TPP NPs retained an average of 98% of the added water over a 48-hour period. CT-Acacia NPs showed high moisture absorption but lower moisture retention capacity, which indicates their competency to entrap polar actives in cosmetics and release the encapsulated actives in low polarity skin conditions. The cytotoxicity studies using MTT assay showed that CT NPs made using TPP or Acacia crosslinkers were similarly non-toxic to the human dermal fibroblast cells. Cellular uptake study of NPs observed using live-cell imaging microscopy, proving the great cellular internalisation of CT:TPP NPs and CT-Acacia NPs. Confocal laser scanning microscopy revealed that CT NPs of particle size 530nm containing fluorescein sodium salt as a marker were able to penetrate through the pig skin and gather in the dermis layer. These results show that CT NPs have the ability to deliver the actives and cosmetic components through the skin and to be used as cosmetics and dermal drug delivery system.

Chitosan and Hydroxyapatite Based Biomaterials to Circumvent Periprosthetic Joint Infections

Every year, worldwide, millions of people suffering from joint pain undergo joint replacement. For most patients, joint arthroplasty reduces pain and improve function, though a small fraction will experience implant failure. One of the main reasons includes prosthetic joint infection (PJI), involving the prosthesis and adjacent tissues. Few microorganisms (MO) are required to inoculate the implant, resulting in the formation of a biofilm on its surface. Standard treatment includes not only removal of the infected prosthesis but also the elimination of necrotic bone fragments, local and/or systemic administration of antibiotics, and revision arthroplasty with a new prosthesis, immediately after the infection is cleared. Therefore, an alternative to the conventional therapeutics would be the incorporation of natural antimicrobial compounds into the prosthesis. Chitosan (Ch) is a potential valuable biomaterial presenting properties such as biocompatibility, biodegradability, low immunogenicity, wound healing ability, antimicrobial activity, and anti-inflammatory potential. Regarding its antimicrobial activity, Gram-negative and Gram-positive bacteria, as well as fungi are highly susceptible to chitosan. Calcium phosphate (CaP)-based materials are commonly utilized in orthopedic and dentistry for their excellent biocompatibility and bioactivity, particularly in the establishment of cohesive bone bonding that yields effective and rapid osteointegration. At present, the majority of CaP-based materials are synthetic, which conducts to the depletion of the natural resources of phosphorous in the future due to the extensive use of phosphate. CaP in the form of hydroxyapatite (HAp) may be extracted from natural sources as fish bones or scales, which are by-products of the fish food industry. Thus, this review aims to enlighten the fundamental characteristics of Ch and HAp biomaterials which makes them attractive to PJI prevention and bone regeneration, summarizing relevant studies with these biomaterials to the field.

An overview of chitosan and its application in infectious diseases

Infectious diseases, such as the coronavirus disease-19, SARS virus, Ebola virus, and AIDS, threaten the health of human beings globally. New viruses, drug-resistant bacteria, and fungi continue to challenge the human efficacious drug bank. Researchers have developed a variety of new antiviral and antibacterial drugs in response to the infectious disease crisis. Meanwhile, the development of functional materials has also improved therapeutic outcomes. As a natural material, chitosan possesses good biocompatibility, bioactivity, and biosafety. It has been proven that the cooperation between chitosan and traditional medicine greatly improves the ability of anti-infection. This review summarized the application and design considerations of chitosan-composed systems for the treatment of infectious diseases, looking forward to providing the idea of infectious disease therapy.

Hybrid Acrylated Chitosan and Thiolated Pectin Cross-Linked Hydrogels with Tunable Properties

We developed and characterized a new hydrogel system based on the physical and chemical interactions of pectin partially modified with thiol groups and chitosan modified with acrylate end groups. Gelation occurred at high pectin thiol ratios, indicating that a low acrylated chitosan concentration in the hydrogel had a profound effect on the cross-linking. Turbidity, Fourier transform infrared spectroscopy, and free thiol determination analyses were performed to determine the relationships of the different bonds inside the gel. At low pH values below the pKa of chitosan, more electrostatic interactions were formed between opposite charges, but at high pH values, the Michael-type addition reaction between acrylate and thiol took place, creating harder hydrogels. Swelling experiments and Young’s modulus measurements were performed to study the structure and properties of the resultant hydrogels. The nanostructure was examined using small-angle X-ray scattering. The texture profile analysis showed a unique property of hydrogel adhesiveness. By implementing changes in the preparation procedure, we controlled the hydrogel properties. This hybrid hydrogel system can be a good candidate for a wide range of biomedical applications, such as a mucosal biomimetic surface for mucoadhesive testing.

Development and In Vivo Characterization of Probiotic Lysate-Treated Chitosan Nanogel as a Novel Biocompatible Formulation for Wound Healing

Wound healing is a physiological reaction to tissue injuries which plays a crucial role in replacing the destroyed tissues. Probiotics produce valuable compounds that possess antibacterial and anti-inflammatory activities, immunomodulatory effects, and angiogenesis traits leading to the promotion of wound healing. Chitosan nanostructures have versatile properties making them quickly produced into gels, scaffolds, nanoparticles, beads, and sponge structures that can be incorporated into wound healing processes. In the current study, three formulations from nanogel consisting of probiotic supernatant (Lactobacillus reuteri, Lactobacillus fermentum, and Bacillus subtilis sp. natto)-loaded chitosan nanogels were prepared from the culture of corresponding cultures. The chitosan nanogels were previously characterized by Zetasizer, FTIR, and TEM. The prepared formulations' effectiveness and dressing activity were assessed by evaluating wound closure and histological trials in Sprague-Dawley rats. The results indicated that all probiotic lysate formulations have advantages over the wound healing process. However, Bacillus subtilis natto has a better wound healing quality, which is well known in pathology examination. The favorable effects of probiotic lysate nanogels, including the reasonable wound closing rate, good wound appearance, and satisfactory histological observation via in vivo examination, suggest it as a promising nominee for wound healing purposes.

Effectiveness of chitosan-propolis nanoparticle against Enterococcus faecalis biofilms in the root canal

Background

The successful outcome of endodontic treatment depends on controlling the intra-radicular microbial biofilm by effective instrumentation and disinfection using various irrigants and intracanal medicaments. Instrumentation alone cannot effectively debride the root canals specially due to the complex morphology of the root canal system. A number of antibiotics and surfactants are being widely used in the treatment of biofilms however, the current trend is towards identification of natural products in disinfection. The aim of the study was to determine the antibacterial effect of chitosan-propolis nanoparticle (CPN) as an intracanal medicament against Enterococcus faecalis biofilm in root canal.

Methods

240 extracted human teeth were sectioned to obtain 6 mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9 mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into eight groups (n = 30) according to the intracanal medicament placed: group I: saline, group II: chitosan, group III: propolis100 µg/ml (P100), group IV: propolis 250 µg/ml (P250), group V: chitosan-propolis nanoparticle 100 µg/ml (CPN100), group VI: chitosan-propolis nanoparticle 250 µg/ml (CPN250), group VII: calcium hydroxide(CH) and group VIII: 2% chlorhexidine (CHX) gel. Dentine shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of day one, three and seven. The non-parametric Kruskal Wallis and Mann–Whitney tests were used to compare the differences in reduction of CFUs between all groups and probability values of p < 0.05 were set as the reference for statistically significant results. The scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to CPNs. The effectiveness of CPNs were also evaluated against E. faecalis isolated obtained from patients having failed root canal treatment.

Results

The treatments of chitosan, P100, P250, CPN100, CPN250, CH and 2% CHX reduced the CFUs significantly compared to saline (p < .05). On day one and three, at 200 and 400-μm, CPN250 showed significant reduction of CFUs compared to all other groups (p < .05), while CPN100 was significantly better than other groups (p < .05) except CPN250 and 2% CHX. On day seven, at 200-μm CPN250 showed significant reduction of CFUs compared to all other groups (p < .05) except CPN100 and CHX, while at 400 μm CPN250 showed similar effectiveness as CPN100, CH and 2% CHX. SEM images showed root canal dentin treated with CPN250 had less coverage with E. faecalis bacteria similarly, CLSM images also showed higher percentage of dead E. faecalis bacteria with CPN250 than to CPN100.

Conclusion

CPN250 was the most effective in reducing E. faecalis colonies on day one, three at both depths and at day seven CPN250 was equally effective as CPN100 and 2% CHX.

Development of delivery system based on marine chitosan: Encapsulationand release kinetic study of antioxidant peptides from chitosan microparticle

The present work aims to encapsulate goby fish protein hydrolysate (GPH), endowed with antioxidant activity, through ionic gelation process using blue crab chitosan (CH) and tripolyphosphate anions and to evaluate the structural, thermal and antioxidant properties of the elaborated microparticles (MPs). The GPH-loaded MPs present spherical shape as seen by scanning electron microscopy (SEM) images and positive zeta potential. The increase of loaded GPH concentration led to the increase of encapsulation efficiency (EE) and to the reduction of the particle size. In fact, MPs, loaded with 2 and 5 mg/ml GPH, had EE values of 44 and 58% and mean particles size of 4.81 and 3.78 μm, respectively. Furthermore, thermogravimetric analysis (TGA) profiles revealed the enhanced thermal stability of encapsulated biopeptides compared to the free ones. Release kinetic data showed a Fickian diffusion behavior which follows swelling and a diffusion-controlled mechanism for peptides liberation. Finally, as opposed to unloaded MPs, an improvement of the antioxidant activity of the loaded MPs with biopeptides was observed.

Red blood cell-hitchhiking chitosan nanoparticles for prolonged blood circulation time of vitamin K1

Nanocarriers have been extensively applied for intravascular drug delivery. However, rapid clearance from circulation by mononuclear phagocyte system has limited their applications. Erythrocytes carriers are potential solutions to overcome the limitations of nanocarriers and considered to be ideal natural carriers for drug delivery because of their unique properties. The purpose of this work is to combine nanocarriers with erythrocytes carriers for sustained release and prolonged circulation time of vitamin K₁. Chitosan nanoparticles loading VK₁ (VK-CSNPs) were prepared using ionotropic gelation method, which was optimized using box-behnken design and response surface methodology. VK-CSNPs adsorbed onto red blood cells (RBC-VK-CSNPs) rapidly via electrostatic interactions. The exposure of phosphatidylserine, osmotic fragility and turbulence fragility of RBC loading nanoparticles were investigated to study the toxicity of nanoparticles to erythrocytes. In vivo pharmacokinetic study indicated that C_max, AUC and MRT of RBC-VK-CSNPs group were remarkably higher than that of VK-CSNPs group. Flow cytometry showed VK-CSNPs steadily retained on the surface of RBC for a long time without affecting the circulation profiles of RBC themselves. The nanoparticles carried on RBC released drug, desorbed and were eliminated in vivo. Therefore, the circulation time of RBC-hitchhiking chitosan nanoparticles was greatly prolonged compared with nanoparticles alone. RBC-hitchhiking could be a valuable hybrid strategy for prolonging the in vivo life of nanocarriers.

Formulation and Evaluation of Microwave-Modified Chitosan-Curcumin Nanoparticles-A Promising Nanomaterials Platform for Skin Tissue Regeneration Applications Following Burn Wounds

Improved physicochemical properties of chitosan-curcumin nanoparticulate carriers using microwave technology for skin burn wound application are reported. The microwave modified low molecular weight chitosan variant was used for nanoparticle formulation by ionic gelation method nanoparticles analyzed for their physicochemical properties. The antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa cultures, cytotoxicity and cell migration using human dermal fibroblasts-an adult cell line-were studied. The microwave modified chitosan variant had significantly reduced molecular weight, increased degree of deacetylation and decreased specific viscosity. The nanoparticles were nano-sized with high positive charge and good dispersibility with entrapment efficiency and drug content in between 99% and 100%, demonstrating almost no drug loss. Drug release was found to be sustained following Fickian the diffusion mechanism for drug release with higher cumulative drug release observed for formulation (F)2. The microwave treatment does not render a destructive effect on the chitosan molecule with the drug embedded in the core of nanoparticles. The optimized formulation precluded selected bacterial strain colonization, exerted no cytotoxic effect, and promoted cell migration within 24 h post application in comparison to blank and/or control application. Microwave modified low molecular weight chitosan-curcumin nanoparticles hold potential in delivery of curcumin into the skin to effectively treat skin manifestations.

Aerosolized hyaluronic acid decorated, ferulic acid loaded chitosan nanoparticle: A promising asthma control strategy

Vibrating mesh nebulizers are recognized as the most efficient actuation technique over conventional inhalers for drug deposition. This study explored hyaluronic acid (HA) decorated, ferulic acid (FA) loaded chitosan (CS) nanoparticle (FACHA) aerosolized using vibrating mesh nebulizer as strategic combination of drug, nanocarrier and delivery device for effective asthma control. FACHA exhibited spherical morphology with suitable size (164.2 ± 9.7 nm), zeta potential (24.0 ± 0.5 mV), entrapment efficiency (EE%) (65.0 ± 1.5), loading capacity (LC%) (18.5 ± 0.4) and mass median aerodynamic diameter (MMAD) of 1.81 ± 0.15 µm, ascertaining efficient drug deposition. In vivo inhalation toxicity assessment confirmed safety, while, FACHA prophylaxis mitigated inflammation, airway hypersensitivity and remodelling in ovalbumin (OVA) induced mice models. The results thus accentuated the role of pro-pulmonary surface chemistry conferred by HA functionalization that improved 1) thermal stability (thermogravimetric analysis - TGA) and 2) therapeutic efficacy of FA, by facilitating better interaction and transportation across mucus barrier, which otherwise suffers poor bioavailability and rapid metabolism.

Polysaccharide nanoparticles for oral controlled drug delivery: the role of drug-polymer and interpolymer interactions

Introduction: The oral route still represents the most popular way of administering drugs; nowadays oral administration faces new challenges, in particular with regards to the delivery of APIs that are poorly absorbed and sensitive to degradation such as macromolecules and biotechnological drugs. Nanoparticles are promising tools for the efficient delivery of these drugs to the gastrointestinal tract. Areas covered:Approaches and techniques for the formulation of drugs, with particular focus on the preparation of polysaccharide nanoparticles obtained by non-covalent interactions. Expert opinion:Polysaccharide-based nanoparticulate systems offer the opportunity to address some of the issues posed by biotechnological drugs, as well as by small molecules, with problems of stability/intestinal absorption, by exploiting the capability of the polymer to establish non-covalent bonds with functional groups in the chemical structure of the API. This area of research will continue to grow, provided that these drug delivery technologies will efficaciously be translated into systems that can be manufactured on a large scale under GMP conditions. Industrial scale-up represents the biggest obstacle to overcome in view of the transformation of very promising results obtained on lab scale into medicinal products. To do that, an effort toward the simplification of the process and technologies is necessary.

Comprehensive Survey on Nanobiomaterials for Bone Tissue Engineering Applications

One of the most important ideas ever produced by the application of materials science to the medical field is the notion of biomaterials. The nanostructured biomaterials play a crucial role in the development of new treatment strategies including not only the replacement of tissues and organs, but also repair and regeneration. They are designed to interact with damaged or injured tissues to induce regeneration, or as a forest for the production of laboratory tissues, so they must be micro-environmentally sensitive. The existing materials have many limitations, including impaired cell attachment, proliferation, and toxicity. Nanotechnology may open new avenues to bone tissue engineering by forming new assemblies similar in size and shape to the existing hierarchical bone structure. Organic and inorganic nanobiomaterials are increasingly used for bone tissue engineering applications because they may allow to overcome some of the current restrictions entailed by bone regeneration methods. This review covers the applications of different organic and inorganic nanobiomaterials in the field of hard tissue engineering.

In vitro and in vivo studies of nanoparticles of chitosan-Pandanus tectorius fruit extract as new alternative treatment for hypercholesterolemia via Scavenger Receptor Class B type 1 pathway

Pandanus tectorius fruit, a natural product rich in tangeretin and ethyl caffeate, has been reported to have potential as anti-hypercholesterolemia agent via Scavenger Receptor Class B type 1 (SR-B1) pathway. However, due to its semi-polar properties, P. tectorius extract exhibits poor solubility when used as a medical remedy. The extract’s solubility can potentially be improved through a synthesis of nanoparticles of chitosan-P. tectorius fruit extract. This can also increase the extract’s SR-B1 gene expression activity. To date, no studies of nanoparticles of chitosan-P. tectorius fruit extract and its pathway via SR-B1 have been published anywhere. In this study, cytotoxicity properties against HepG2 were explored by MTT. Then luciferase assay was used to detect their effectiveness in increasing SR-B1 activity. An in vivo study using Sprague dawley was carried out to observe the extract nanoparticles’ effectiveness in reducing the cholesterol levels and the toxicity property in rat’s liver. As the results showed, the extract nanoparticles had no cytotoxic activity against HepG2 cells and exhibited higher SR-B1 gene expression activity than the non-nanoparticle form. As the in vivo study proved, nanoparticle treatment can reduce the levels of TC (197%), LDL (360%), and TG (109%), as well as increase the level of HDL cholesterol by 150%, in comparison to those for the untreated high-cholesterol diet group. From the toxicity study, it was found that there was non-toxicity in the liver. It can be concluded that nanoparticles of chitosan-P. tectorius fruit extract successfully increased P. tectorius fruit extract’s effectiveness in reducing hypercholesterolemia via SR-B1 pathway. Hence, it can be suggested that nanoparticles of chitosan-P. tectorius fruit extract is safe and suitable as an alternative treatment for controlling hypercholesterolemia via SR-B1 pathway.

Biodegradable self-assembled nanoparticles of PEG-PLGA amphiphilic diblock copolymer as a promising stealth system for augmented vinpocetine brain delivery

Vinpocetine (VNP), a semisynthetic drug, is utilized for the treatment of cerebrovascular and memory disorders. This work aimed at formulation of biodegradable VNP long-circulating nanoparticles utilizing Polyethylene glycol methyl ether-block-poly lactide-co-glycolide (PEG-PLGA) copolymer to surmount the drug drawbacks including low oral bioavailability and short elimination half-life. VNP nanoparticles were formulated using nanoprecipitation technique. A 2⁴ factorial design was applied to assess the impact of formulation and process variables on the nanoparticles' characteristics. Statistical analysis revealed that nanoparticles size (Y₁) significantly increased with increasing PEG-PLGA amount (X₁), poly-vinyl alcohol concentration (X₂), and PLGA content (X₄), while decreased with increasing sonication time (X₃). Furthermore, the entrapment efficiency (Y₂) was positively affected by both PEG-PLGA amount and PLGA content, while negatively affected by poly-vinyl alcohol concentration. The optimized formulation prepared using 200 mg of PEG-PLGA polymer (PEG: PLGA 2000: 4,500), 0.5% polyvinyl alcohol with sonication time of 60 s achieved spherical shape with particle size of 43 nm and drug entrapment of 82%. A significant bioavailability enhancement of VNP with marked prolongation of the in vivo systemic exposure of the drug and increased brain levels has also been achieved following intraperitoneal administration in Wistar rats. Thus, the optimized formulation could be regarded as a promising stealth nanocarrier that could surmount the drug pitfalls and enhance its brain delivery.

Designing, structural determination and biological effects of rifaximin loaded chitosan- carboxymethyl chitosan nanogel

Due to the poor solubility and permeability of rifaximin (RFX), it is not effective against intracellular pathogens although it shows strong activity against most bacteria. To develop an effective mucoadhesive drug delivery system with a targeted release in bacterial infection site, RFX-loaded chitosan (CS)/carboxymethyl-chitosan (CMCS) nanogel was designed and systematically evaluated. FTIR, DSC, and XRD demonstrated that the nanogel was formed by interactions between the positively charged NH₃⁺ on CS and CMCS, and the negatively charged COO on CMCS. RFX was encapsulated into the optimized nanogel in amorphous form. The nanogel was a uniform spherical shape with a mean diameter of 171.07 nm. It had excellent sustained release, strong mucin binding ability, and pH-responsive properties of quicker swelling and release at acidic pH. It showed low hemolytic ratio and high antioxidant activity. The present investigation indicated that the CS-nanogel could be potentially used as a promising bacterial responsiveness drug delivery system.

Phospholipid complex-loaded self-assembled phytosomal soft nanoparticles: evidence of enhanced solubility, dissolution rate, ex vivo permeability, oral bioavailability, and antioxidant potential of mangiferin

In this study, self-assembled phytosomal soft nanoparticles encapsulated with phospholipid complex (MPLC SNPs) using a combination of solvent evaporation and nanoprecipitation method were developed to enhance the biopharmaceutical and antioxidant potential of MGN. The mangiferin-Phospholipon® 90H complex (MPLC) was produced by the solvent evaporation method and optimized using central composite design (CCD). The optimized MPLC was converted into MPLC SNPs using the nanoprecipitation method. The physicochemical and functional characterization of MPLC and MPLC SNPs was carried out by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffractometer (PXRD), proton nuclear magnetic resonance (¹H-NMR), solubility, in vitro dissolution, oral bioavailability, and in vivo antioxidant studies. A CCD formed stable MPLC with the optimal values of 1:1.76, 50.55 °C, and 2.02 h, respectively. Characterization studies supported the formation of a complex. MPLC and MPLC SNPs both enhanced the aqueous solubility (~ 32-fold and ~ 39-fold), dissolution rate around ~ 98% via biphasic release pattern, and permeation rate of ~ 97%, respectively, compared with MGN and MGN SNPs. Liver function tests and in vivo antioxidant studies exhibited that MPLC SNPs significantly preserved the CCl₄-intoxicated liver marker and antioxidant marker enzymes, compared with MGN SNPs. The oral bioavailability of MPLC SNPs was increased appreciably up to ~ 10-fold by increasing the main pharmacokinetic parameters such as C_max, T_max, and AUC. Thus, MPLC SNPs could be engaged as a nanovesicle delivery system for improving the biopharmaceutical and antioxidant potential of MGN. Graphical abstract.

Effects of high intensity interval training (up & downward running) with BCAA/nano chitosan on Foxo3 and SMAD soleus muscles of aging rat

AIMS

The aim of this study was investigate the effects of 8 weeks of high intensity interval training (HIIT, up & downward running) with BCAA/nano chitosan on Foxo3 and SMAD soleus muscles of aging rats.

MAIN METHODS

In this experimental study thirty male rats were randomly divided into six groups of control, BCAA with Nano chitosan (Supplement, (Sup)), upslope running, downslope running, upslope running+Sup, and downslope running+Sup that each groups consist of 6 rats. The exercise training was performed HIIT 8 weeks 3 session per weeks with incrementally intensity 12 to 52 m/m in 7sets (Slop 0 to 15^o) during 8 weeks. BCAA coated with chitosan nanoparticles (84 mg/kg) and gavage to supplementation groups, 3 days per weeks for eight weeks. The animals were feed with standard rat chow (Normal diet, 2.87 kcal/g, 15% of energy from fat). At the end of protocol the rat was sacrifice and soleus muscle was fix and frieze for IHC with H&E and gene expression analysis.

KEY FINDINGS

The results of this study showed that Foxo3 gene expression in the Upslope running + Sup and Downslope running + Sup groups showed a significant decrease (p ≤ 0.05) compared to the control group. The mRNA of Smad also showed that only the Upslope running + Sup group had a significant decrease compared to the control group (p ≤ 0.05).

SIGNIFICANCE

It seems that, BCAA/nano chitosan supplementation along with exercise training in a variety of ways (Up & down slope running) can control the damage caused by Foxo3 and Smad transcription factors. That, control of these factors can minimize age-related atrophy.

Characteristics, Cryoprotection Evaluation and In Vitro Release of BSA-Loaded Chitosan Nanoparticles

Chitosan nanoparticles (CS-NPs) are under increasing investigation for the delivery of therapeutic proteins, such as vaccines, interferons, and biologics. A large number of studies have been taken on the characteristics of CS-NPs, and very few of these studies have focused on the microstructure of protein-loaded NPs. In this study, we prepared the CS-NPs by an ionic gelation method, and bovine serum albumin (BSA) was used as a model protein. Dynamic high pressure microfluidization (DHPM) was utilized to post-treat the nanoparticles so as to improve the uniformity, repeatability and controllability. The BSA-loaded NPs were then characterized for particle size, Zeta potential, morphology, encapsulation efficiency (EE), loading capacity (LC), and subsequent release kinetics. To improve the long-term stability of NPs, trehalose, glucose, sucrose, and mannitol were selected respectively to investigate the performance as a cryoprotectant. Furthermore, trehalose was used to obtain re-dispersible lyophilized NPs that can significantly reduce the dosage of cryoprotectants. Multiple spectroscopic techniques were used to characterize BSA-loaded NPs, in order to explain the release process of the NPs in vitro. The experimental results indicated that CS and Tripolyphosphate pentasodium (TPP) spontaneously formed the basic skeleton of the NPs through electrostatic interactions. BSA was incorporated in the basic skeleton, adsorbed on the surface of the NPs (some of which were inlaid on the NPs), without any change in structure and function. The release profiles of the NPs showed high consistency with the multispectral results.