Advances in using chitosan-based nanoparticles for in vitro and in vivo drug and gene delivery

Nanomaterials and methods for cancer therapy: 2D materials, biomolecules, and molecular dynamics simulations

This review explores the potential of biomolecule-based nanomaterials, i.e., protein, peptide, nucleic acid, and polysaccharide-based nanomaterials, in cancer nanomedicine. It highlights the wide range of design possibilities for creating multifunctional nanomedicines using these biomolecule-based nanomaterials. This review also analyzes the primary obstacles in cancer nanomedicine that can be resolved through the usage of nanomaterials based on biomolecules. It also examines the unique in vivo characteristics, programmability, and biological functionalities of these biomolecule-based nanomaterials. This summary outlines the most recent advancements in the development of two-dimensional semiconductor-based nanomaterials for cancer theranostic purposes. It focuses on the latest developments in molecular simulations and modelling to provide a clear understanding of important uses, techniques, and concepts of nanomaterials in drug delivery and synthesis processes. Finally, the review addresses the challenges in molecular simulations, and generating, analyzing, and developing biomolecule-based and two-dimensional semiconductor-based nanomaterials, and highlights the barriers that must be overcome to facilitate their application in clinical settings.

Loratadine Loaded Chitosan Tannic Acid Nanoparticles as Anti-Proliferative Agent Against Breast Cancer: In-silico, in-vitro and Cell Studies

Purpose

This study aims to prepare Loratadine-loaded chitosan/tannic acid nanoparticles (LOR-CS/TAN NPs) through ionic gelation to be used as an anti-proliferative agent to aid in overcoming breast cancer propagation.

Methods

First, in-silico virtual screening was carried out to select the most appropriate anti-histaminic drug based on its inhibitory effect on the H1-histamine receptor, resulting in the selection of Loratadine (LOR). Molecular interaction between LOR with chitosan (CS), a positively charged polymer, and hyaluronan, a negatively charged polymer, was investigated separately through molecular docking, leading to the selection of CS. Optimization was carried out using Box Behnken Design, with concentrations of CS, LOR, and tannic acid (TAN) as independent variables. The optimized nanoparticles were then examined through morphological and physicochemical studies. Cell studies against the MCF-7 breast cancer cell line were conducted to assess cytotoxicity, cell cycle, apoptosis, and necrosis.

Results

The optimum formulation was determined to be CS (0.2% w/v), LOR (1:2 weight ratio to CS), and TAN (1:30.6 weight ratio to CS). The optimized LOR-CS/TAN NPs exhibited a size of 283 nm, a polydispersity index (PDI) of 0.102, and an entrapment efficiency of 78%, along with sustained drug release for 24 hours. The results demonstrated that LOR-CS/TAN NPs possess higher anti-cancer activity compared to free LOR. This enhanced activity is attributed to the synergistic effect of the drug and the designed nanoparticle, particularly due to the presence of tannic acid.

Conclusion

In conclusion, Loratadine-loaded chitosan/tannic acid nanoparticles (LOR-CS/TAN NPs) demonstrated enhanced anti-cancer activity against the MCF-7 breast cancer cell line. The synergistic effect of Loratadine and the nanoparticle system, particularly due to the presence of tannic acid, resulted in higher cytotoxicity compared to free Loratadine. These findings suggest that LOR-CS/TAN NPs have significant potential as a novel anti-proliferative agent for breast cancer therapy.

Chitosan-Based Nanoformulations: Preclinical Investigations, Theranostic Advancements, and Clinical Trial Prospects for Targeting Diverse Pathologies

Chitosan, a biocompatible and biodegradable polymer, has attracted significant interest in the development of nanoformulations for targeted drug delivery and therapeutic applications. The versatility of chitosan lies in its modifiable functional groups, which can be tailored to diverse applications. Nanoparticles derived from chitosan and its derivatives typically exhibit a positive surface charge and mucoadhesive properties, enabling them to adhere to negatively charged biological membranes and gradually release therapeutic agents. This comprehensive review investigates the manifold roles of chitosan-based nanocarriers, ranging from preclinical research to theranostic applications and clinical trials, across a spectrum of diseases, including neurological disorders, cardiovascular diseases, cancer, wound healing, gastrointestinal disorders, and pulmonary diseases. The exploration starts with an overview of preclinical studies, emphasizing the potential of chitosan-based nanoformulations in optimizing drug delivery, improving therapeutic outcomes, and mitigating adverse effects in various disease categories. Advancements in theranostic applications of chitosan-based nanoformulations highlight their adaptability to diverse diseases. As these nanoformulations progress toward clinical translation, this review also addresses the regulatory challenges associated with their development and proposes potential solutions.

Unlocking the potential of RGD-conjugated gold nanoparticles: a new frontier in targeted cancer therapy, imaging, and metastasis inhibition

In the rapidly evolving field of cancer therapeutics, the potential of gold nanoparticles (AuNPs) conjugated with RGD peptides has emerged as a promising avenue for targeted therapy and imaging. Despite numerous studies demonstrating the effectiveness of RGD-conjugated AuNPs in specifically targeting tumor cells and enhancing radiation therapy (RT), a comprehensive review of these advancements is currently lacking. This review aims to fill this critical gap in the literature. Our analysis reveals that RGD-conjugated AuNPs have shown significant promise in improving the diagnosis and treatment of various types of cancer, including breast cancer. However, the full potential of this technology is yet to be realized. The development of multifunctional nanoplatforms incorporating AuNPs has opened new horizons for targeted therapy, dual-mode imaging, and inhibition of tumor growth and metastasis. This review is of paramount importance as it provides a comprehensive overview of the current state of research in this area, and highlights the areas where further research is needed. It is hoped that this review will inspire further investigations into this promising nanotechnology, ultimately leading to improved cancer diagnosis and therapy. Therefore, the findings presented in this review underscore the potential of AuNPs conjugated with RGD peptides as a revolutionary approach in cancer therapeutics. It is our fervent hope that this review will serve as a catalyst for further research in this exciting field.

Nanotechnology-Based Drug Delivery Systems for Treating Acute Kidney Injury

Acute kidney injury (AKI) is a disease that is characterized by a rapid decline in renal function and has a relatively high incidence in hospitalized patients. Sepsis, renal hypoperfusion, and nephrotoxic drug exposure are the main causes of AKI. The major therapy measures currently include supportive treatment, symptomatic treatment, and kidney transplantation. These methods are supportive treatments, and their results are not satisfactory. Fortunately, many new treatments that markedly improve the AKI therapy efficiency are emerging. These include antioxidant therapy, ferroptosis therapy, anti-inflammatory therapy, autophagy therapy, and antiapoptotic therapy. In addition, the development of nanotechnology has further promoted therapeutic effects on AKI. In this review, we highlight recent advances in the development of nanocarriers for AKI drug delivery. Emphasis has been placed on the latest developments in nanocarrier modification and design. We also summarize the applications of different nanocarriers in AKI treatment. Finally, the advantages and challenges of nanocarrier applications in AKI are summarized, and several nanomedicines that have been approved for clinical trials to treat diverse kidney diseases are listed.

Endocytosis: the match point of nanoparticle-based cancer therapy

Nanomedicine has inspired a ground-breaking strategy for cancer therapy. By intelligently assembling diverse moieties to form nanoparticles, numerous functionalities such as controlled release, synergistic efficiency, and in situ killing can be achieved. The emerging nanoparticles have been designed with elevated targeting efficiency as targeting cancer cells is the primary requirement for nanoparticles. However, effective targeting does not guarantee therapeutic effects as endocytosis is a prerequisite for nanoparticles to exert effects. The recent decade has witnessed the rapid development of endocytosis-oriented nanoparticles, and this review subtly analyzes, categorizes, and exemplifies these nanoparticles according to their biological internalization patterns, and the correlation between the endocytosis mechanism and the property of nanoparticles is bridged. Based on the interdisciplinary vision, the present challenges and future perspectives of nanoparticle design for successful endocytosis are discussed, highlighting the potential strategies for the future development of endocytosis-oriented nanoparticles, thus facilitating the endocytosis-oriented strategy from bench to bedside. The undeniable fact is that endocytosis-oriented nanoparticles will definitely bring new blood to the next generation of advanced cancer therapies.

Microfluidic Controlled Self-Assembly of Polylactide (PLA)-Based Linear and Graft Copolymers into Nanoparticles with Diverse Morphologies

This study outlines the microfluidic (MF) controlled self-assembly of polylactide (PLA)-based linear and graft copolymers. The PLA-based copolymers (PLA-Cs) were synthesized through a convenient one-pot/one-step ROP/RAFT technique. Three distinct vinyl monomers-triethylene glycol methacrylate (TEGMA), 2-hydroxypropyl methacrylate (HPMA), and N-(2-hydroxypropyl) methacrylamide (HPMAA) were employed to prepare various copolymers: linear thermoresponsive polylactide-b-poly(triethylene glycol methacrylate) (PLA-b-PTEGMA), graft pseudothermoresponsive poly[N-(2-hydroxypropyl)] methacrylate-g-polylactide (PHPMA-g-PLA), and graft amphiphilic poly[N-(2-hydroxypropyl)] methacrylamide-g-polylactide (PHPMAA-g-PLA). The MF technology was utilized for the controlled self-assembly of these PLA-based BCs in a solution, resulting in a range of nanoparticle (NP) morphologies. The thermoresponsive PLA-b-PTEGMA diblock copolymer formed thermodynamically stable micelles (Ms) through kinetically controlled assemblies. Similarly, employing MF channels led to the self-assembly of PHPMA-g-PLA, yielding polymersomes (PSs) with adjustable sizes under the same solution conditions. Conversely, the PHPMAA-g-PLA copolymer generated worm-like particles (Ws). The analysis of resulting nano-objects involves techniques such as transmission electron microscopy, dynamic light scattering investigations (DLS), and small-angle X-ray scattering (SAXS). More specifically, the thermoresponsive behavior of PLA-b-PTEGMA and PHPMA-g-PLA nano-objects is validated through variable-temperature DLS, TEM, and SAXS methods. Furthermore, the study explored the specific interactions between the formed Ms, PSs, and/or Ws with proteins in human blood plasma, utilizing isothermal titration calorimetry.

Nano-delivery platforms for bacterial gene transformation: suitability and challenges

Nano-scale particles (NPs) have gained increased interest as non-viral vectors for nucleic acid delivery due to their ability to penetrate through unabraded cell membranes. The previous studies performed have evaluated the nanomaterials for their microbial transformation proficiency but have not compared the relative efficacy. The present study aims to identify the most proficient nano-delivery vehicle among the chemically synthesized/functionalized non-metal oxide, metal/metal oxide, and carbon-based (carbon nanotube (CNT), graphene oxide (GO)) nanomaterial(s) (NMs) for the transformation of two gram-negative bacteria, i.e., Escherichia coli and Agrobacterium tumefaciens. The microscopy and spectroscopy studies helped to identify the interaction, adhesion patterns, transformation efficiencies, better delivery, and expression of the target gfp gene by use of NMs. Loading of pgfp on all NMs imparted protection to DNAse I attack except ZnO NPs with maximum by chitosan, layered double hydroxide (LDH), and GO NM-plasmid DNA conjugates. The CNTs and GO significantly enhanced the extra- and intra-cellular protein content, respectively, in both bacteria. However, GO and CNT significantly decreased the cell viability in a time-dependent manner while AuNPs exhibited negligible cell toxicity. Therefore, this study identified the comparative efficiency of metal/metal oxide, non-metal oxide, and carbon nanomaterials with AuNPs as the most biosafe while LDH and chitosan NPs being the most proficient alternative tools for the genetic transformation of gram-negative bacteria by simple incubation method.

Redox-Responsive Polymeric Nanoparticle for Nucleic Acid Delivery and Cancer Therapy: Progress, Opportunities, and Challenges

Cancer development and progression of cancer are closely associated with the activation of oncogenes and loss of tumor suppressor genes. Nucleic acid drugs (e.g., siRNA, mRNA, and DNA) are widely used for cancer therapy due to their specific ability to regulate the expression of any cancer-associated genes. However, nucleic acid drugs are negatively charged biomacromolecules that are susceptible to serum nucleases and cannot cross cell membrane. Therefore, specific delivery tools are required to facilitate the intracellular delivery of nucleic acid drugs. In the past few decades, a variety of nanoparticles (NPs) are designed and developed for nucleic acid delivery and cancer therapy. In particular, the polymeric NPs in response to the abnormal redox status in cancer cells have garnered much more attention as their potential in redox-triggered nanostructure dissociation and rapid intracellular release of nucleic acid drugs. In this review, the important genes or signaling pathways regulating the abnormal redox status in cancer cells are briefly introduced and the recent development of redox-responsive NPs for nucleic acid delivery and cancer therapy is systemically summarized. The future development of NPs-mediated nucleic acid delivery and their challenges in clinical translation are also discussed.

Cellulase-immobilized chitosan-coated magnetic nanoparticles for saccharification of lignocellulosic biomass

Devising and consolidating cost-effective and greener technologies for sustainable energy production pertain to some of the most pressing needs of the present times. Bioconversion of abundantly available lignocellulosic materials into fermentable sugars to produce biofuels involves the cost-extensive requirement of hydrolytic enzymes called cellulases. Cellulases are highly selective and eco-friendly biocatalysts responsible for deconstruction of complex polysaccharides into simple sugars. Currently, immobilization of cellulases is being carried out on magnetic nanoparticles functionalized with suitable biopolymers such as chitosan. Chitosan, a biocompatible polymer, exhibits high surface area, chemical/thermal stability, functionality, and reusability. The chitosan-functionalized magnetic nanocomposites (Ch-MNCs) present a nanobiocatalytic system that enables easy retrieval, separation, and recycling of cellulases, thereby offering a cost-effective and sustainable approach for biomass hydrolysis. These functional nanostructures show enormous potential owing to certain physicochemical and structural features that have been discussed in a comprehensive manner in this review. It provides an insight into the synthesis, immobilization, and application of cellulase immobilized Ch-MNCs for biomass hydrolysis. This review aims to bridge the gap between sustainable utilization and economic viability of employing replenishable agro-residues for cellulosic ethanol production by incorporating the recently emerging nanocomposite immobilization approach.

Novel Nanoencapsulation Technology and its Potential Role in Bile Acid-Based Targeted Gene Delivery to the Inner Ear

Hearing loss impacts a large proportion of the global population. Damage to the inner ear, in particular the sensitive hair cells, can impact individuals for the rest of their lives. There are very limited options for interventions after damage to these cells has occurred. Targeted gene delivery may provide an effective means to trigger appropriate differentiation of progenitor cells for effective replacement of these sensitive hair cells. There are several hurdles that need to be overcome to effectively deliver these genes. Nanoencapsulation technology has previously been used for the delivery of pharmaceuticals, proteins and nucleic acids, and may provide an effective means of delivering genes to trigger appropriate differentiation. This review investigates the background of hearing loss, current advancements and pitfalls of gene delivery, and how nanoencapsulation may be useful.

The recent advancement in the PLGA-based thermo-sensitive hydrogel for smart drug delivery

To date, hydrogels have opened new prospects for potential applications for drug delivery. The thermo-sensitive hydrogels have the great potential to provide more effective and controllable release of therapeutic/bioactive agents in response to changes in temperature. PLGA is a safe FDA-approved copolymer with good biocompatibility and biodegradability. Recently, PLGA-based formulation have attracted a lot of interest for thermo-sensitive hydrogels. Thermo-sensitive PLGA-based hydrogels provide the delivery system with good spatial and temporal control, and have been widely applied in drug delivery. This review is focused on the recent progression of the thermo-sensitive and biodegradable PLGA-based hydrogels that have been reported for smart drug delivery to the different organs. Eventually, future perspectives and challenges of thermo-sensitive PLGA-based hydrogels are discussed briefly.

Nanomaterials against intracellular bacterial infection: from drug delivery to intrinsic biofunction

Fighting intracellular bacteria with strong antibiotics evading remains a long-standing challenge. Responding to and regulating the infectious microenvironment is crucial for treating intracellular infections. Sophisticated nanomaterials with unique physicochemical properties exhibit great potential for precise drug delivery towards infection sites, along with modulating infectious microenvironment via their instinct bioactivity. In this review, we first identify the key characters and therapeutic targets of intracellular infection microenvironment. Next, we illustrate how the nanomaterials physicochemical properties, such as size, charge, shape and functionalization affect the interaction between nanomaterials, cells and bacteria. We also introduce the recent progress of nanomaterial-based targeted delivery and controlled release of antibiotics in intracellular infection microenvironment. Notably, we highlight the nanomaterials with unique intrinsic properties, such as metal toxicity and enzyme-like activity for the treatment of intracellular bacteria. Finally, we discuss the opportunities and challenges of bioactive nanomaterials in addressing intracellular infections.

A nanoengineered topical transmucosal cisplatin delivery system induces anti-tumor response in animal models and patients with oral cancer

Despite therapeutic advancements, oral cavity squamous cell carcinoma (OCSCC) remains a difficult disease to treat. Systemic platinum-based chemotherapy often leads to dose-limiting toxicity (DLT), affecting quality of life. PRV111 is a nanotechnology-based system for local delivery of cisplatin loaded chitosan particles, that penetrate tumor tissue and lymphatic channels while avoiding systemic circulation and toxicity. Here we evaluate PRV111 using animal models of oral cancer, followed by a clinical trial in patients with OCSCC. In vivo, PRV111 results in elevated cisplatin retention in tumors and negligible systemic levels, compared to the intravenous, intraperitoneal or intratumoral delivery. Furthermore, PRV111 produces robust anti-tumor responses in subcutaneous and orthotopic cancer models and results in complete regression of carcinogen-induced premalignant lesions. In a phase 1/2, open-label, single-arm trial (NCT03502148), primary endpoints of efficacy (≥30% tumor volume reduction) and safety (incidence of DLTs) of neoadjuvant PRV111 were reached, with 69% tumor reduction in ~7 days and over 87% response rate. Secondary endpoints (cisplatin biodistribution, loco-regional control, and technical success) were achieved. No DLTs or drug-related serious adverse events were reported. No locoregional recurrences were evident in 6 months. Integration of PRV111 with current standard of care may improve health outcomes and survival of patients with OCSCC.

Chitosan-modified nanocarriers as carriers for anticancer drug delivery: Promises and hurdles

With the advent of drug delivery, various polymeric materials are being explored to fabricate numerous nanocarriers. Each polymer is associated with a few characteristics attributes which further facilitate its usage in drug delivery. One such polymer is chitosan (CS), which is extensively employed to deliver a variety of drugs to various targets, especially to cancer cells. The desired properties like biological origin, bio-adhesive, biocompatibility, the scope of chemical modification, biodegradability and controlled drug release make it a highly rough after polymer in pharmaceutical nanotechnology. The present review attempts to compile various chemical modifications on CS and showcase the outcomes of the derived nanocarriers, especially in cancer chemotherapy and drug delivery.

Biopolymeric Nanoparticles-Multifunctional Materials of the Future

Nanotechnology plays an important role in biological research, especially in the development of delivery systems with lower toxicity and greater efficiency. These include not only metallic nanoparticles, but also biopolymeric nanoparticles. Biopolymeric nanoparticles (BPNs) are mainly developed for their provision of several advantages, such as biocompatibility, biodegradability, and minimal toxicity, in addition to the general advantages of nanoparticles. Therefore, given that biopolymers are biodegradable, natural, and environmentally friendly, they have attracted great attention due to their multiple applications in biomedicine, such as drug delivery, antibacterial activity, etc. This review on biopolymeric nanoparticles highlights their various synthesis methods, such as the ionic gelation method, nanoprecipitation method, and microemulsion method. In addition, the review also covers the applications of biodegradable polymeric nanoparticles in different areas-especially in the pharmaceutical, biomedical, and agricultural domains. In conclusion, the present review highlights recent advances in the synthesis and applications of biopolymeric nanoparticles and presents both fundamental and applied aspects that can be used for further development in the field of biopolymeric nanoparticles.

Targeted Transposition of Minicircle DNA Using Single-Chain Antibody Conjugated Cyclodextrin-Modified Poly (Propylene Imine) Nanocarriers

Among non-viral vectors, cationic polymers, such as poly(propylene imine) (PPI), play a prominent role in nucleic acid delivery. However, limitations of polycationic polymer-based DNA delivery systems are (i) insufficient target specificity, (ii) unsatisfactory transgene expression, and (iii) undesired transfer of therapeutic DNA into non-target cells. We developed single-chain antibody fragment (scFv)-directed hybrid polyplexes for targeted gene therapy of prostate stem cell antigen (PSCA)-positive tumors. Besides mono-biotinylated PSCA-specific single-chain antibodies (scFv(AM1-P-BAP)) conjugated to neutravidin, the hybrid polyplexes comprise β-cyclodextrin-modified PPI as well as biotin/maltose-modified PPI as carriers for minicircle DNAs encoding for Sleeping Beauty transposase and a transposon encoding the gene of interest. The PSCA-specific hybrid polyplexes efficiently delivered a GFP gene in PSCA-positive tumor cells, whereas control hybrid polyplexes showed low gene transfer efficiency. In an experimental gene therapy approach, targeted transposition of a codon-optimized p53 into p53-deficient HCT116^p53-/-/PSCA cells demonstrated decreased clonogenic survival when compared to mock controls. Noteworthily, p53 transposition in PTEN-deficient H4^PSCA glioma cells caused nearly complete loss of clonogenic survival. These results demonstrate the feasibility of combining tumor-targeting hybrid polyplexes and Sleeping Beauty gene transposition, which, due to the modular design, can be extended to other target genes and tumor entities.

Glutathione targeted tragacanthic acid-chitosan as a non-viral vector for brain delivery of miRNA-219a-5P: An in vitro/in vivo study

Multiple sclerosis (MS) is a progressive chronic demyelinating and neurodegenerative disease. The symptoms could only be diminished through stimulated remyelination. Although administration of microRNA-219a-5P (miR-219) seems to recover the damages, it is hampered by the challenging delivery of genes to the central nervous system across the blood-brain barrier. To enhance the CNS delivery of miR-219, a novel non-viral targeted vector was appraised by conjugating chitosan (Ch) to tragacanthic acid (TA) and glutathione (Glu). The nanoparticles were characterized and injected into the cuprizone model of MS mice to investigate the in vivo features of the resulting polyplex. Transmission electron microscopy, luxol fast blue staining, and proteolipid protein 1 (Plp1) overexpression confirmed more compact myelin sheaths following the administration of the targeted miR-219 nanoparticles and positron emission tomography (PET) scan also demonstrated the reduced inflammation and higher cell regeneration in the brain. Fluorescence microscopy and in vivo imaging were employed to identify miR-219 accumulation patterns in mice. The polyplex led to miR-219 overexpression, crystallin alpha B upregulation, and apolipoprotein E downregulation. It was concluded that glutathione targeted Ch/TA nanoparticles could be exploited as a feasible non-viral vector for miR-219 specific targeting to the brain, miR-219 overexpression and inflammation abatement in MS.

Chitosan-coated pore wall polycaprolactone three-dimensional porous scaffolds fabricated by porogen leaching method for bone tissue engineering: a comparative study on blending technique to fabricate scaffolds

One of the significant challenges in the fabrication of scaffolds for tissue engineering lies in the direct interaction of bioactive agents with cells in the scaffolds matrix, which curbs the effectiveness of bioactive agents resulting in diminished cell recognition and attachment ability of the scaffolds. Here, three-dimensional porous scaffolds were fabricated using polycaprolactone (PCL) and chitosan, by two approaches, i.e., blending and surface coating to compare their overall effectiveness. Blended scaffolds (Chi-PCL) were compared with the scaffolds fabricated using surface coating technique, where chitosan was coated on the pore wall of PCL scaffolds (C-PCL). The C-PCL exhibited a collective improvement in bioactivities of the stem cell on the scaffold, because of the cell compatible environment provided by the presence of chitosan over the scaffolds interface. The C-PCL showed the enhanced cell attachment and proliferation behavior of the scaffolds along with two-fold increase in hemolysis compatibility compared to Chi-PCL. Furthermore, the compression strength in C-PCL increased by 24.52% and 8.62% increase in total percentage porosity compared to Chi-PCL was attained. Along with this, all the bone markers showed significant upregulation in C-PCL scaffolds, which supported the surface coating technique over the conventional methods, even though the pore size of C-PCL was compromised by 19.98% compared with Chi-PCL.

Chitosan-Based Biocompatible Copolymers for Thermoresponsive Drug Delivery Systems: On the Development of a Standardization System

Chitosan is a natural polysaccharide that is considered to be biocompatible, biodegradable and non-toxic. The polymer has been used in drug delivery applications for its positive charge, which allows for adhesion with and recognition of biological tissues via non-covalent interactions. In recent times, chitosan has been used for the preparation of graft copolymers with thermoresponsive polymers such as poly-N-vinylcaprolactam (PNVCL) and poly-N-isopropylamide (PNIPAM), allowing the combination of the biodegradability of the natural polymer with the ability to respond to changes in temperature. Due to the growing interest in the utilization of thermoresponsive polymers in the biological context, it is necessary to increase the knowledge of the key principles of thermoresponsivity in order to obtain comparable results between different studies or applications. In the present review, we provide an overview of the basic principles of thermoresponsivity, as well as a description of the main polysaccharides and thermoresponsive materials, with a special focus on chitosan and poly-N-Vinyl caprolactam (PNVCL) and their biomedical applications.

Nanotechnological Manipulation of Nutraceuticals and Phytochemicals for Healthy Purposes: Established Advantages vs. Still Undefined Risks

Numerous foods, plants, and their bioactive constituents (BACs), named nutraceuticals and phytochemicals by experts, have shown many beneficial effects including antifungal, antiviral, anti-inflammatory, antibacterial, antiulcer, anti-cholesterol, hypoglycemic, immunomodulatory, and antioxidant activities. Producers, consumers, and the market of food- and plant-related compounds are increasingly attracted by health-promoting foods and plants, thus requiring a wider and more fruitful exploitation of the healthy properties of their BACs. The demand for new BACs and for the development of novel functional foods and BACs-based food additives is pressing from various sectors. Unfortunately, low stability, poor water solubility, opsonization, and fast metabolism in vivo hinder the effective exploitation of the potential of BACs. To overcome these issues, researchers have engineered nanomaterials, obtaining food-grade delivery systems, and edible food- and plant-related nanoparticles (NPs) acting as color, flavor, and preservative additives and natural therapeutics. Here, we have reviewed the nanotechnological transformations of several BACs implemented to increase their bioavailability, to mask any unpleasant taste and flavors, to be included as active ingredients in food or food packaging, to improve food appearance, quality, and resistance to deterioration due to storage. The pending issue regarding the possible toxic effect of NPs, whose knowledge is still limited, has also been discussed.

Current trends and challenges in the synthesis and applications of chitosan-based nanocomposites for plants: A review

Chitosan, a low-cost and multipurpose polymer with numerous desired physicochemical and biological properties has been tested for various applications in agriculture, pharmacy, and biomedicine industries. The availability of functional groups along the backbone makes chitosan readily available for other polymers and metal ions to form bio-nanocomposites. Different types of chitosan-based nanocomposites have been designed and tested for the enhancement of chitosan efficiency and ultimately widening the application areas of chitosan in plants. These nanocomposites serve different purposes such as eliciting plant's defence systems against different threats (pathogen attack), antimicrobial agent against bacteria, fungi and viruses, enhancement of nutrient uptake by plants, control release of micro/macronutrients, fungicides and herbicides. In this review, an extensive outlook has been provided (mainly in the last five years) to recent trends and advances in the fabrication and application of chitosan-based composites. Finally, current challenges and future development opportunities of chitosan-based nanocomposites for plants are discussed.

Recombinant overexpression of the Escherichia coli acetyl-CoA carboxylase gene in Synechocystis sp. boosts lipid production

Microalgae have received continued attention as a potential source for biofuel production. However, the lack of suitable strains that provide a lipid-rich biomass and tolerate harsh condition inhibits their industrial application. This report describes an effort to transform Synechocystis sp. with genes encoding acetyl-CoA carboxylase (ACC), a key regulatory enzyme in the lipogenesis pathway, from the white mustard plant (Sinapis alba) and the bacterium Escherichia coli DH5α using chitosan nanoparticles. Although a recombinant plasmid encoding S. alba ACC failed to express, successful transformation was achieved with a recombinant plasmid encoding E. coli DH5α ACC. The successful transformant, Synechocystis sp. PAK13, exhibited increased ACC expression compared with its wild-type parent (11.8 vs. 7.2 ng), which significantly increased its lipid content (by 3.6-fold). Synechocystis sp. PAK13 also exhibited a significant (20%) reduction in photosynthetic pigments, a 1.52-fold higher glucose content and a 3.5-fold lower sucrose content than the wild-type. In conclusion, this report introduces a useful strategy to overexpress the ACC gene in microalgae, creating strains with improved lipid production that are suited to industrial applications.

Mannose receptor targeted bioadhesive chitosan nanoparticles of clofazimine for effective therapy of tuberculosis

Drug-resistant tuberculosis (TB) is one of the most lethal diseases, and it is imperative to exploit an advanced drug formulation for its effective treatment. This work aims to develop a mannose receptor-targeted bioadhesive chitosan nanoparticles for effective drug-resistant tuberculosis treatment. The clofazimine loaded chitosan nanoparticles were formulated; their size, charge, polydispersity (PDI), surface morphology, entrapment efficiency (EE) and in-vitro release pattern were established. Also, cellular uptake study on C2C12 cell lines and anti-mycobacterial activity against H37Rv (a standard strain of Mycobacterium tuberculosis) were evaluated. The particle sizes of formulated chitosan nanoparticles were in the range of 132–184 nm and EE was also found to be between 73 and 95%. The functionalization of bioadhesive chitosan nanoparticles with mannose was confirmed by infrared spectroscopy (FTIR). The uptake studies on the C2C12 cell lines showed that mannosylated nanoparticles were more efficiently internalized when compared to non-targeted nanoparticles. Further, luciferase reporter phage (LRP) assay against H37Rv strain showed that clofazimine nanoparticles were found to be 49.5 times superior in terms of inhibition and anti-mycobacterial activity than free clofazimine. This excellent activity might be attributed to enhanced drug delivery with a promising bioadhesion property of chitosan-based nanoparticles.

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.

Fabrication, characterization and biological evaluation of silymarin nanoparticles against carbon tetrachloride-induced oxidative stress and genotoxicity in rats

This study aimed to synthesize silymarin nanoparticles (SILNPs) using chitosan nanoparticles as a delivery system and to evaluate their protective effects against CCl₄ in rats. Eight groups of male Sprague-Dawley rats were treated for three weeks included the control group, CCl₄-treated group (100 mg/kg b.w twice a week); SIL-treated group (50 mg/lg b.w); the groups treated daily with low dose (LD) or high dose (HD) of SILNPs (25, 50 mg/kg b.w) and the groups treated with CCl₄ plus SIL, SILNPs (LD) or SILNPs (HD). Blood and tissue samples were collected for different assays. The synthesized SILNPs showed a smooth rounded shape with average particle size of 100 ± 2.8 nm. SILNPs contain the same compounds found in raw SIL and the in vitro release of SILNPs continues till 24 h. The in vivo study revealed that SIL and SILNPs at the low or high dose induced a significant improvement in the hematological parameters, liver and kidney function, lipid profile, serum cytokines, gene expression DNA fragmentation and histology of liver and kidney tissue resulted from CCl₄. It could be concluded that SILNPs can be applied in oral delivery formulations with a potential application value for liver disease therapy.

Nanoparticle-Mediated Drug Delivery: Blood-Brain Barrier as the Main Obstacle to Treating Infectious Diseases in CNS

BACKGROUND

Parasitic infections affecting the central nervous system (CNS) present high morbidity and mortality rates and affect millions of people worldwide. The most important parasites affecting the CNS are protozoans (Plasmodium sp., Toxoplasma gondii, Trypanosoma brucei), cestodes (Taenia solium) and free-living amoebae (Acantamoeba spp., Balamuthia mandrillaris and Naegleria fowleri). Current therapeutic regimens include the use of traditional chemicals or natural compounds that have very limited access to the CNS, despite their elevated toxicity to the host. Improvements are needed in drug administration and formulations to treat these infections and to allow the drug to cross the blood-brain barrier (BBB).

METHODS

This work aims to elucidate the recent advancements in the use of nanoparticles as nanoscaled drug delivery systems (NDDS) for treating and controlling the parasitic infections that affect the CNS, addressing not only the nature and composition of the polymer chosen, but also the mechanisms by which these nanoparticles may cross the BBB and reach the infected tissue.

RESULTS

There is a strong evidence in the literature demonstrating the potential usefulness of polymeric nanoparticles as functional carriers of drugs to the CNS. Some of them demonstrated the mechanisms by which drugloaded nanoparticles access the CNS and control the infection by using in vivo models, while others only describe the pharmacological ability of these particles to be utilized in in vitro environments.

CONCLUSION

The scarcity of the studies trying to elucidate the compatibility as well as the exact mechanisms by which NDDS might be entering the CNS infected by parasites reveals new possibilities for further exploratory projects. There is an urgent need for new investments and motivations for applying nanotechnology to control parasitic infectious diseases worldwide.

Usage of natural chitosan membrane obtained from insect corneal lenses as a drug carrier and its potential for point of care tests

Chitosan is an indispensable biopolymer for use as a drug carrier thanks to its non-toxic, biodegradable, biocompatible, antimicrobial, and anti-oxidative nature. In previous studies, chitosan was first dissolved into weak acids and formed into gel, then used for carrying pharmaceutically active compounds such as nanoparticles, capsules, composites, and films. Using the produced chitosan gel after dissolving it in weak acids has advantages, such as ease of processing for loading the required amount of active substance and making the desired shape and size. However, dissolved chitosan loses some of its natural properties such as fibrous structure, crystallinity, and thermal stability. In this study, for the first time, three-dimensional chitosan lenses obtained from an insect's (Tabanus bovinus) compound eyes, with the original shape intact, were tested as a drug carrier. A model drug, quercetin, was loaded into chitosan membrane, and its release profile was examined. Also, a point-of-care test was conducted for both chitin and chitosan membranes. Chitin and chitosan membranes obtained from insect corneal lenses were characterized by using FTIR, TGA, elemental analysis, and surface wettability analysis as well as stereo, binocular, and scanning electron microscopies. It was observed that chitosan membrane could be used as a drug carrier material. Both chitin and chitosan membranes will be improved for lateral flow assay, and these membranes can be tested for other bioengineering applications in further studies.

Simultaneous delivery of anti-miRNA and docetaxel with supramolecular self-assembled "chitosome" for improving chemosensitivity of triple negative breast cancer cells

At present, treating of triple negative breast cancer (TNBC) mainly depends on chemotherapy with more toxic side effects, but the effect is limited and it is highly prone to drug resistance. Gene therapy using anti-microRNAs maybe one of alternative therapeutic strategies. Due to the poor cell permeability and significant in vivo decomposition rate of anti-microRNAs, which limits their clinical application, we developed a core-shell supramolecular nanovector of "chitosome" that were self-assembled from the synthetic amphiphilic chitosan derivatives. The constructed chitosomes could co-load hydrophilic anti-miR-21 and hydrophobic docetaxel (DTX) into one combo nanocarrier with entrapment efficiency of more than 80%, as well as spherical morphology and average particle size of 90 nm. In comparison with the naked ones, anti-miR-21 encapsulated with chitosomes showed significantly increased cellular transfection and stability against degradation by nuclease in serum. Compared with DTX or anti-miR-21 formulations used alone, the co-delivery of the two drugs with the combo chitosome obtained improved chemosensitivity of TNBC cells to DTX treatment through their synergistic mechanisms. Taken together, the developed chitosome could be a promising candidate for simultaneous delivery of insoluble chemotherapeutic drugs and gene agents for TNBC therapy. Graphical abstract.

In situ formation of injectable hydrogels for chronic wound healing

Hydrogels have been widely used in wound healing treatment over the past decade.

Challenges and strategies in drug delivery systems for treatment of pulmonary infections

Inhalation therapy has been reported as the most effective treatment for respiratory bacterial infections due to the increasing relevance of drug bioavailability. Drug delivery systems (DDS) have the capacity to overcome pulmonary biological barriers limiting the bioavailability of inhaled anti-infectives. This is important to eradicate bacterial infections and to prevent the development of bacterial resistance. Despite substantial efforts in the field, the current state-of-the-art often fails to achieve those goals, and we still observe increasing bacterial resistance. We give a brief insight on benefits and challenges in pulmonary delivery of anti-infectives. In the context of drug delivery development for pulmonary infections, particularly focusing on Pseudomonas aeruginosa (PA) infections, this mini review will critically discuss the main requirements, as well as the recent strategies of drug delivery system synthesis and preparation. Finally, interaction of DDS with crucial pulmonary biological barriers will be of great importance for the success of future applications of the developed DDS.

Functional lipid polymeric nanoparticles for oral drug delivery: Rapid mucus penetration and improved cell entry and cellular transport

To improve Biopharmaceutics Classification System class IV drug bioavailability, mucus and underlying intestinal epithelial barriers must be overcome. Hydrophilic nanoparticle coatings may hinder cellular uptake and transport. We integrated hydrophilic, detachable poly(N-(2-hydroxypropyl) methacrylamide) with vitamin B12-modified chitosan into lipid polymeric nanoparticles (H/VC-LPNs) to enhance mucus penetration, intracellular uptake, and transepithelial absorption. Multiple particle tracking revealed accelerated mucus diffusion into porcine mucus in vitro. The nanoparticles increased uptake and intracellular distribution in Caco-2 cells, which may involve intrinsic factor receptor-mediated endocytosis and intercellular tight junctions. Integration of improved mucus penetration and intracellular absorption was confirmed by in vitro internalization kinetics in HT29-MTX/Caco-2 co-cultures and in vivo distribution, transport, and mouse Peyer's patch absorption. H/VC-LPNs substantially increased curcumin bioavailability in rats. A nanocarrier with a dissociable shell, receptor-mediated intracellular penetration, and paracellular transport may be promising for oral curcumin delivery. This study identified the key factors involved in oral bioavailability enhancement.

pH-Sensitive Chitosan-Heparin Nanoparticles for Effective Delivery of Genetic Drugs into Epithelial Cells

Chitosan has been extensively studied as a genetic drug delivery platform. However, its efficiency is limited by the strength of DNA and RNA binding. Expecting a reduced binding strength of cargo with chitosan, we proposed including heparin as a competing polyanion in the polyplexes. We developed chitosan–heparin nanoparticles by a one-step process for the local delivery of oligonucleotides. The size of the polyplexes was dependent on the mass ratio of polycation to polyanion. The mechanism of oligonucleotide release was pH-dependent and associated with polyplex swelling and collapse of the polysaccharide network. Inclusion of heparin enhanced the oligonucleotide release from the chitosan-based polyplexes. Furthermore, heparin reduced the toxicity of polyplexes in the cultured cells. The cell uptake of chitosan–heparin polyplexes was equal to that of chitosan polyplexes, but heparin increased the transfection efficiency of the polyplexes two-fold. The application of chitosan–heparin small interfering RNA (siRNA) targeted to vascular endothelial growth factor (VEGF) silencing of ARPE-19 cells was 25% higher. Overall, chitosan–heparin polyplexes showed a significant improvement of gene release inside the cells, transfection, and gene silencing efficiency in vitro, suggesting that this fundamental strategy can further improve the transfection efficiency with application of non-viral vectors.

Natural product drug delivery: A special challenge?

Natural products have a long-standing and critical role in drug development and medical use. The structural and physicochemical properties of natural products, while derived evolutionarily to be effective in living systems, may create challenges in translation to a pharmaceutical product. Molecular complexity, low solubility, functional group reactivity and general instability are among the challenges that typically need to be overcome. This review looks at some of the ways that natural products have been formulated and delivered to enable the successful application of these vitally important medicines to patients.

Optimization of Chitosan-α-casein Nanoparticles for Improved Gene Delivery: Characterization, Stability, and Transfection Efficiency

Among non-viral vectors, the cationic polymer chitosan has gained attention as a gene delivery system. We hypothesized that the addition of casein into the nanoparticle's structure would facilitate a proper gene transfer. The work herein presented aimed to optimize the production method of chitosan-casein nanoparticles (ChiCas NPs) and to test their ability as a gene delivery system. ChiCas NPs formulation optimization was carried out by analyzing several characteristics such as NP size, zeta potential, and chitosan and casein incorporation efficacy. The best formulation developed presented small and homogenous particle size (around 335 nm) and positive zeta potential (≈ + 38 mV), and showed to be stable for 34 weeks both, at 4°C and 20°C. The particles were further used to entrap or to adsorb DNA and form NPs-DNA complexes. In vitro transfection studies, carried out in COS-7 cells, suggested a low transfection efficiency of the different NPs:DNA ratios tested, comparatively to the positive control. Nonetheless, we could observe that the complexes with larger sizes presented better transfection results than those with smaller diameters. To conclude, ChiCas NPs have great technological potential since the preparation process is very simple, and the DNA incorporation efficacy is very high and shows to be physically very stable. The NPs:DNA ratio still needs to be optimized with the aim of achieving better transfection results and being able to anticipate a high gene expression on DNA-based vaccination studies.

Optimized Preparation of Levofloxacin Loaded Polymeric Nanoparticles

In this work, poly(lactic-co-glycolic acid) (PLGA) and chitosan (CS) nanoparticles were synthesized with the purpose of encapsulating levofloxacin (LEV). A thorough study has been carried out in order to optimize the preparation of LEV-loaded polymeric nanoparticles (NPs) suitable for parenteral administration. Changes in the preparation method, in the organic solvent nature, in the pH of the aqueous phase, or in the temperature were investigated. To the authors´ knowledge, a systematic study in order to improve the LEV nanocarrier characteristics and the yield of drug encapsulation has not been carried out to date. The physicochemical characterization of the NPs, their encapsulation efficiency (EE), and the in vitro release of LEV revealed that the best formulation was the emulsion-solvent evaporation method using dichloromethane as organic solvent, which renders suitable LEV loaded PLGA NPs. The morphology of these NPs was investigated using TEM. Their antimicrobial activities against several microorganisms were determined in vitro measuring the minimum inhibitory concentration (MIC). The results show that the use of these loaded LEV PLGA nanoparticles has the advantage of the slow release of the antibiotic, which would permit an increase in the time period between administrations as well as to decrease the side effects of the drug.

Nanotheranostics, a future remedy of neurological disorders

INTRODUCTION

Effective therapy of various neurological disorders is hindered on account of the failure of various therapeutics crossing blood-brain-barrier (BBB). Nanotheranostics has emerged as a cutting-edge unconventional theranostic nanomedicine, capable of realizing accurate diagnosis together with effective and targeted delivery of therapeutics across BBB to the unhealthy regions of the brain for potential clinical success.

AREAS COVERED

We have tried to review the current status of nanotheranostic based approaches followed to manage neurological disorders. The focus has been majorly laid on to explore various theranostic nanoparticles and their application potential towards image-guided neurotherapies. Additionally, the usefulness of exceptional diagnostic, imaging techniques including magnetic resonance imaging and fluorescence imaging are being discussed by highlighting their promising opportunities in the detection, diagnosis, and treatment of the neurological disorders.

EXPERT OPINION

Inimitable diagnostic and therapeutic potential of nanotheranostics have accomplished the aim of personalized therapies by governing the therapeutic efficacy of the system along with facilitating patient pre-selection grounded on non-invasive imaging, thereby predicting the responses of patients to nanomedicine treatments. While these accomplishments are encouraging, they are still the minority and demands for a continuous effort to improve sensitivity and precision in screening/diagnosis along with improving therapeutic efficacy in various neural disorders.

A transport model and constitutive equation for oppositely charged polyelectrolyte mixtures with application to layer-by-layer assembly

We develop a general framework for transport of polyions, solvent and salt, with intended application to Layer-by-Layer (LbL) assembly of polyelectrolyte monolayers (PEMs). The formulation for the first time includes electrostatics, chemical potential gradients, and mechanical stress gradients as driving forces for mass transport. The general model allows all species to be mobile throughout the process and avoids the assumptions of stepwise instantaneous equilibrium and/or immobilized structures typical of previous approaches, while reducing to these models in appropriate limits. A simple constitutive equation is derived for a mixture of oppositely charged polyelectrolytes that accounts for network strand dilution and cross-chain ion pairing by appending reactive terms to the Smoluchowski probability diffusion equation for network strand end-to-end vectors. The resulting general framework encompasses the Poisson equation describing the electrostatic potential distribution, an osmotic pressure balance, a stress constitutive equation, and a generalized flux law of polymer transport. The computational domain is split into a PEM phase and an external solution phase with an appropriate boundary condition derived for the interface between the two. The mobile species (water and small salt ions) are taken to be in a state of dynamic equilibrium with their distributions enslaved to the perturbations in the two polyion compositions. The proposed model captures the swelling response of PEM films to external solutions. For the first time, we studied the effects of the temporal evolution of electrostatic and stress distribution on the rate of chain loss and absorption during rinsing and dipping of an idealized and arbitrarily selected and rigid brush layer into external solutions. The temporal evolution provides a kinetic basis for the ability of LbL films to grow under conditions that thermodynamics alone suggests would cause them to be washed away and to account for partial desorption during washing. The proposed transport framework constitutes a solid basis for eventual quantitative modeling of LbL assembly and transport in polyion networks more generally.