Multi-ion-crosslinked nanoparticles with pH-responsive characteristics for oral delivery of protein drugs

Rutin-loaded chitosan nanoparticles alleviated Freund's adjuvant induced rheumatoid arthritis via modulating oxidative stress and inflammatory parameters in Wistar rats

Rheumatoid arthritis (RA) is the most common chronic inflammatory disease, primarily affecting the joints and with stromal tissue dysregulation causing chronic inflammation and joint destruction. Rutin is a natural flavonoid with potential therapeutic properties in chronic destructive conditions including rheumatoid diseases. In this study, the protective effects of rutin nanoformulation in an animal model of rheumatoid arthritis caused by Freund's complete adjuvant (FCA) were investigated. Sixty male rats were randomly divided into ten groups including normal, negative control, prednisolone 10 mg/kg (positive control), 3 doses of rutin (15, 30, 45mg/kg), rutin nanoparticles (15, 30, 45 mg/kg), and nanoparticle without rutin, for 28 days. Different behavioral parameters including the open field test, acetone drop test, hot plate test, Von Frey test, and inclined plane test were evaluated. Serum levels of glutathione (GSH), catalase, and nitric oxide as well as histopathological analyses were measured in different groups. Also, matrix metalloproteinase (MMP)-2 and MMP-9 activity were appraised by gelatin zymography. The injection of FCA prolonged the rats' immobility duration in comparison to the control group. Rheumatoid arthritis induction also increased nitric oxide and decreased GSH and catalase levels, while these effects were reversed in the groups that received nanoparticles containing rutin and prednisolone. Rutin nanoparticles suppressed MMP-9 and activated MMP-2. Also, this rutin drug delivery system plays a significant role in the improvement of histopathological symptoms. Considering the improvement of behavioral and tissue symptoms and the modulation of the level of inflammatory cytokines, nanoparticles containing rutin can be proposed as a suitable approach in the management of patients with rheumatoid arthritis.

Exploring the antimicrobial potential of chitosan nanoparticles: synthesis, characterization and impact on Pseudomonas aeruginosa virulence factors

The escalating antibiotic resistance observed in bacteria poses a significant threat to society, with the global prevalence of resistant strains of Pseudomonas aeruginosa on the rise. Addressing this challenge necessitates exploring strategies that would complement existing antimicrobial agents, e.g. by substances mitigating bacterial virulence without eliciting selective pressure for resistance emergence. In this respect, free-form chitosan has demonstrated promising efficacy, prompting our investigation into reinforcing its effects through nanoparticle formulations. Our study focuses on the preparation of chitosan nanoparticles under suitable conditions while emphasizing the challenges associated with stability that can affect biological activity. These challenges are mitigated by introducing quaternized chitosan, which ensures colloidal stability in the culture media. Our approach led to the production of trimethylchitosan nanoparticles with a median size of 103 nm, circularity of 0.967, and a charge of 14.9 ± 3.1 mV, stable within a one-month period in a water stock solution, showing promising attributes for further valorization. Furthermore, the study delves into the antimicrobial activity of trimethylchitosan nanoparticles on Pseudomonas aeruginosa and confirms the benefits of both nanoformulation and modification of chitosan, as our prepared nanoparticles inhibit 50% of the bacterial population at concentration ≥160 mg L-1 within tested strains. Additionally, we identified a concentration of 5 mg L-1 that no longer impedes bacterial growth, allowing reliable verification of the effect of the prepared nanoparticles on Pseudomonas aeruginosa virulence factors, including motility, protease activity, hemolytic activity, rhamnolipids, pyocyanin, and biofilm production. Although trimethylchitosan nanoparticles exhibit promise as an effective antibiofilm agent (reducing biofilm development by 50% at concentrations ranging from 80 to 160 mg L-1) their impact on virulence manifestation is likely not directly associated with quorum sensing. Instead, it can probably be attributed to non-specific interactions with the bacterial surface. This exploration provides valuable insights into the potential of quaternized chitosan nanoparticles in addressing Pseudomonas aeruginosa infections and underscores the multifaceted nature of their antimicrobial effects.

Exploring the potential of pH-sensitive polymers in targeted drug delivery

The pH-sensitive polymers have attained significant attention in the arena of targeted drug delivery (TDD) because of their exceptional capability to respond to alteration in pH in various physiological environments. This attribute aids pH-sensitive polymers to act as smart carriers for therapeutic agents, transporting them precisely to target locations while curtailing the release of drugs in off-targeted sites, thereby diminishing side effects. Many pH-responsive polymers in TDD have revealed promising results, with increased therapeutic efficacy and decreased toxic effects. Several pH-sensitive polymers, including, hydroxy-propyl-methyl cellulose, poly (methacrylic acid) (Eudragit series), poly (acrylic acid), and chitosan, have been broadly studied for their myriad applications in the management of various types of diseases. Additionally, the amalgamation of pH-sensitive polymers with, additive manufacturing techniques like 3D printing, has resulted in the progression of novel drug delivery systems that regulate drug release in a controlled manner. Herein, types of pH-sensitive polymers in TDD are systemically reviewed. We have briefly discussed the nanocarriers employed for the delivery of various pH-sensitive polymers in TDD. Finally, miscellaneous applications of pH-sensitive polymers are discussed thoroughly with special attention to the implication of 3D printing in pH-sensitive polymers.

Preparation, Characterization and Drug Delivery Research of γ-Polyglutamic Acid Nanoparticles: A Review

γ-Polyglutamic acid is a kind of biomaterial and environmentally friendly polymer material with the characteristics of water solubility and good biocompatibility. It has a wide range of applications in medicine, food, cosmetics and other fields. This article reviews the preparation, characterization and medical applications of γ-polyglutamic acid nanoparticles. Nanoparticles prepared by using γ- polyglutamic acid not only had the traditional advantages of enhancing drug stability and slow-release effect, but also were simple to prepare without any biological toxicity. The current methods of nanoparticle preparation mainly include the ion gel method and solvent exchange method, which use the total electrostatic force, van der Waals force, hydrophobic interaction force and hydrogen bond force between molecules to embed materials with different characteristics. At present, there are more and more studies on the use of γ-polyglutamic acid to encapsulate drugs, and the research on the mechanism of its encapsulation and sustained release has gradually matured. The development and application of polyglutamic acid nanoparticles have broad prospects.

The Advancement and Obstacles in Improving the Stability of Nanocarriers for Precision Drug Delivery in the Field of Nanomedicine

Nanocarriers have emerged as a promising class of nanoscale materials in the fields of drug delivery and biomedical applications. Their unique properties, such as high surface area- tovolume ratios and enhanced permeability and retention effects, enable targeted delivery of therapeutic agents to specific tissues or cells. However, the inherent instability of nanocarriers poses significant challenges to their successful application. This review highlights the importance of nanocarrier stability in biomedical applications and its impact on biocompatibility, targeted drug delivery, long shelf life, drug delivery performance, therapeutic efficacy, reduced side effects, prolonged circulation time, and targeted delivery. Enhancing nanocarrier stability requires careful design, engineering, and optimization of physical and chemical parameters. Various strategies and cutting-edge techniques employed to improve nanocarrier stability are explored, with a focus on their applications in drug delivery. By understanding the advances and challenges in nanocarrier stability, this review aims to contribute to the development and implementation of nanocarrier- based therapies in clinical settings, advancing the field of nanomedicine.

A chitosan-coated lentinan-loaded calcium alginate hydrogel induces broad-spectrum resistance to plant viruses by activating Nicotiana benthamiana calmodulin-like (CML) protein 3

Control of plant virus diseases largely depends on the induced plant defence achieved by the external application of synthetic chemical inducers with the ability to modify defence-signalling pathways. However, most of the molecular mechanisms underlying these chemical inducers remain unknown. Here, we developed a chitosan-coated lentinan-loaded hydrogel and discovered how it protects plants from different virus infections. The hydrogel was synthesized by coating chitosan on the surface of the calcium alginate-lentinan (LNT) hydrogel (SL-gel) to form a CSL-gel. CSL-gels exhibit the capacity to prolong the stable release of lentinan and promote Ca2+ release. Application of CSL-gels on the root of plants induces broad-spectrum resistance against plant viruses (TMV, TRV, PVX and TuMV). RNA-seq analysis identified that Nicotiana benthamiana calmodulin-like protein gene 3 (NbCML3) is upregulated by the sustained release of Ca2+ from the CSL-gel, and silencing and overexpression of NbCML alter the susceptibility and resistance of tobacco to TMV. Our findings provide evidence that this novel and synthetic CSL-gel strongly inhibits the infection of plant viruses by the sustainable release of LNT and Ca2+ . This study uncovers a novel mode of action by which CSL-gels trigger NbCML3 expression through the stable and sustained release of Ca2+ .

Oral Microalgae-Nano Integrated System against Radiation-Induced Injury

The increasing applications of ionizing radiation in society raise the risk of radiation-induced intestinal and whole-body injury. Astaxanthin is a powerful antioxidant to reduce the reactive oxygen generated from radiation and the subsequent damage. However, the oral administration of astaxanthin remains challenging owing to its low solubility and poor bioavailability. Herein, we facilely construct an orally used microalgae-nano integrated system (SP@ASXnano) against radiation-induced intestinal and whole-body injury, combining natural microalgae Spirulina platensis (SP) with astaxanthin nanoparticles (ASXnano). SP and ASXnano show complementation in drug delivery to improve distribution in the intestine and blood. SP displays limited gastric drug loss, prolonged intestinal retention, constant ASXnano release, and progressive degradation. ASXnano improves drug solubility, gastric stability, cell uptake, and intestinal absorption. SP and ASXnano have synergy in many aspects such as anti-inflammation, microbiota protection, and fecal short-chain fatty acid up-regulation. In addition, the system is ensured with biosafety for long-term administration. The system organically combines the properties of microalgae and nanoparticles, which was expected to expand the medical application of SP as a versatile drug delivery platform.

Oral insulin delivery: Barriers, strategies, and formulation approaches: A comprehensive review

Diabetes Mellitus is characterized by a hyperglycemic condition which can either be caused by the destruction of the beta cells or by the resistance developed against insulin in the cells. Insulin is a peptide hormone that regulates the metabolism of carbohydrates, proteins, and fats. Type 1 Diabetes Mellitus needs the use of Insulin for efficient management. However invasive methods of administration may lead to reduced adherence by the patients. Hence there is a need for a non-invasive method of administration. Oral Insulin has several merits over the conventional method including patient compliance, and reduced cost, and it also mimics endogenous insulin and hence reaches the liver by the portal vein at a higher concentration and thereby showing improved efficiency. However oral Insulin must pass through several barriers in the gastrointestinal tract. Some strategies that could be utilized to bypass these barriers include the use of permeation enhancers, absorption enhancers, use of suitable polymers, use of suitable carriers, and other agents. Several formulation types have been explored for the oral delivery of Insulin like hydrogels, capsules, tablets, and patches which have been described briefly by the article. A lot of attempts have been made for developing oral insulin delivery however none of them have been commercialized due to numerous shortcomings. Currently, there are several formulations from the companies that are still in the clinical phase, the success or failure of some is yet to be seen in the future.

Aptamer-modified M cell targeting liposomes for oral delivery of macromolecules

There is an urgent demand for non-invasive and high compliance delivery systems of macromolecules for long-term therapy. However, oral administration of macromolecules is hindered by low permeability and instability in the gastrointestinal (GI) tract. Therefore, we developed a novel aptamer-modified liposomes (Apt-Lip) with M cell targeting for oral delivery of exenatide (EXT). Firstly, we optimized aptamers to M cells by Cell-SELEX and aptamer truncations. The selected aptamer T-M3 (Apt-T-M3) with high binding affinity (K_d = 176 ± 108 nM) and specificity was modified on the surface of liposomes for targeting M cells. Liposomes were formulated by microfluidics system and characterized in terms of morphology, hydrodynamic diameter, zeta potential, and the efficiency of encapsulation. In comparison with non-targeting liposomes, cell uptake in M cells was significantly enhanced by Apt-Lip. Similarly, the transport efficiency of EXT was 2-fold increase using Apt-Lip in M cells. Additionally, the transepithelial electrical resistance (TEER) of M cell monolayers is significantly reduced. In ex vivo intestinal absorption study, Apt-Lip was proved to possess significantly high intestinal absorption in Peyer's patches (PPs) and M cells-specific targeting capacity. Consequently, Apt-Lip promoted the EXT transport could base not only on M cell mediated transport, but also on enhancement of paracellular permeability. In conclusion, the present study supported Apt-Lip as a promising M cell targeted delivery system for oral delivery of macromolecules.

Nano-Sized Fucoidan Interpolyelectrolyte Complexes: Recent Advances in Design and Prospects for Biomedical Applications

The marine polysaccharide fucoidan (FUC) is a promising polymer for pharmaceutical research and development of novel drug delivery systems with modified release and targeted delivery. The presence of a sulfate group in the polysaccharide makes FUC an excellent candidate for the formation of interpolyelectrolyte complexes (PECs) with various polycations. However, due to the structural diversity of FUC, the design of FUC-based nanoformulations is challenging. This review describes the main strategies for the use of FUC-based PECs to develop drug delivery systems with improved biopharmaceutical properties, including nanocarriers in the form of FUC-chitosan PECs for pH-sensitive oral delivery, targeted delivery systems, and polymeric nanoparticles for improved hydrophobic drug delivery (e.g., FUC-zein PECs, core-shell structures obtained by the layer-by-layer self-assembly method, and self-assembled hydrophobically modified FUC particles). The importance of a complex study of the FUC structure, and the formation process of PECs based on it for obtaining reproducible polymeric nanoformulations with the desired properties, is also discussed.

Nanocarriers as a Delivery Platform for Anticancer Treatment: Biological Limits and Perspectives in B-Cell Malignancies

Nanoparticle-based therapies have been proposed in oncology research using various delivery methods to increase selectivity toward tumor tissues. Enhanced drug delivery through nanoparticle-based therapies could improve anti-tumor efficacy and also prevent drug resistance. However, there are still problems to overcome, such as the main biological interactions of nanocarriers. Among the various nanostructures for drug delivery, drug delivery based on polymeric nanoparticles has numerous advantages for controlling the release of biological factors, such as the ability to add a selective targeting mechanism, controlled release, protection of administered drugs, and prolonging the circulation time in the body. In addition, the functionalization of nanoparticles helps to achieve the best possible outcome. One of the most promising applications for nanoparticle-based drug delivery is in the field of onco-hematology, where there are many already approved targeted therapies, such as immunotherapies with monoclonal antibodies targeting specific tumor-associated antigens; however, several patients have experienced relapsed or refractory disease. This review describes the major nanocarriers proposed as new treatments for hematologic cancer, describing the main biological interactions of these nanocarriers and the related limitations of their use as drug delivery strategies.

Natural Polysaccharide-Based Nanodrug Delivery Systems for Treatment of Diabetes

In recent years, natural polysaccharides have been considered as the ideal candidates for novel drug delivery systems because of their good biocompatibility, biodegradation, low immunogenicity, renewable source and easy modification. These natural polymers are widely used in the designing of nanocarriers, which possess wide applications in therapeutics, diagnostics, delivery and protection of bioactive compounds or drugs. A great deal of studies could be focused on developing polysaccharide nanoparticles and promoting their application in various fields, especially in biomedicine. In this review, a variety of polysaccharide-based nanocarriers were introduced, including nanoliposomes, nanoparticles, nanomicelles, nanoemulsions and nanohydrogels, focusing on the latest research progress of these nanocarriers in the treatment of diabetes and the possible strategies for further study of polysaccharide nanocarriers.

Chitosan Nanoparticle Encapsulation of Antibacterial Essential Oils

Chitosan is the most suitable encapsulation polymer because of its natural abundance, biodegradability, and surface functional groups in the form of free NH₂ groups. The presence of NH₂ groups allows for the facile grafting of functionalized molecules onto the chitosan surface, resulting in multifunctional materialistic applications. Quaternization of chitosan's free amino is one of the typical chemical modifications commonly achieved under acidic conditions. This quaternization improves its ionic character, making it ready for ionic-ionic surface modification. Although the cationic nature of chitosan alone exhibits antibacterial activity because of its interaction with negatively-charged bacterial membranes, the nanoscale size of chitosan further amplifies its antibiofilm activity. Additionally, the researcher used chitosan nanoparticles as polymeric materials to encapsulate antibiofilm agents (such as antibiotics and natural phytochemicals), serving as an excellent strategy to combat biofilm-based secondary infections. This paper provided a summary of available carbohydrate-based biopolymers as antibiofilm materials. Furthermore, the paper focuses on chitosan nanoparticle-based encapsulation of basil essential oil (Ocimum basilicum), mandarin essential oil (Citrus reticulata), Carum copticum essential oil ("Ajwain"), dill plant seed essential oil (Anethum graveolens), peppermint oil (Mentha piperita), green tea oil (Camellia sinensis), cardamom essential oil, clove essential oil (Eugenia caryophyllata), cumin seed essential oil (Cuminum cyminum), lemongrass essential oil (Cymbopogon commutatus), summer savory essential oil (Satureja hortensis), thyme essential oil, cinnamomum essential oil (Cinnamomum zeylanicum), and nettle essential oil (Urtica dioica). Additionally, chitosan nanoparticles are used for the encapsulation of the major essential components carvacrol and cinnamaldehyde, the encapsulation of an oil-in-water nanoemulsion of eucalyptus oil (Eucalyptus globulus), the encapsulation of a mandarin essential oil nanoemulsion, and the electrospinning nanofiber of collagen hydrolysate-chitosan with lemon balm (Melissa officinalis) and dill (Anethum graveolens) essential oil.

pH-Responsive Self-Assembling Peptide-Based Biomaterials: Designs and Applications

Stimuli-responsive peptide-based biomaterials are increasingly gaining interest for various specific and targeted treatments, including drug delivery and tissue engineering. Among all stimuli, pH can be especially useful because endogenous pH changes are often associated with abnormal microenvironments. pH-Responsive amino acids and organic linkers can be easily incorporated into peptides that self-assemble into various nanostructures. Thus, these largely biocompatible and easily tunable platforms are ideal candidates for drug release and as fibrous materials capable of mimicking the native extracellular matrix. In this review, we highlight common design motifs and mechanisms of pH-responsiveness in self-assembling peptide-based biomaterials, focusing on recent advances of these biomaterials applied in drug delivery and tissue engineering. Finally, we suggest future challenges and areas for potential development in pH-responsive self-assembling peptide-based biomaterials.

Osmundea sp. macroalgal polysaccharide-based nanoparticles produced by flash nanocomplexation technique

The macroalgae-derived polysaccharides' biological potential has been explored due to their attractive intrinsic properties such as biocompatibility, biodegradability, and their ability to conjugate with other compounds. In particular, in the drug delivery systems field, the anionic macroalgae polysaccharides have been combined with cationic compounds through ionotropic gelation and/or bulk mixing. However, these techniques did not assure reproducibility, and the stability of nanoparticles is undesired. To overcome these limitations, herein, the polysaccharide extracted from Osmundea sp. was used to produce nanoparticles through the flash nanocomplexation technique. This approach rapidly mixed the negative charge of macroalgae polysaccharide with a positive chitosan charge on a millisecond timescale. Further, diclofenac (an anti-inflammatory drug) was also incorporated into complex nanoparticles. Overall, the gathered data showed that hydrodynamic diameter nanoparticles values lower than 100 nm, presenting a narrow size distribution and stability. Also, the diclofenac exhibited a targeted and sustained release profile in simulating inflammatory conditions. Likewise, the nanoparticles showed excellent biological properties, evidencing their suitability to be used to treat inflammatory skin diseases.

Control and Preparation of Quaternized Chitosan and Carboxymethyl Chitosan Nanoscale Polyelectrolyte Complexes Based on Reactive Flash Nanoprecipitation

Nanoscale polyelectrolyte complex materials have been extensively investigated for their promising application in protocell, drug carriers, imaging, and catalysis. However, the conventional preparation approach involving positive and negative polyelectrolytes leads to large size, wide size distribution, instability, and aggregation due to the nonhomogeneous mixing process. Herein, we employ reactive flash nanoprecipitation (RFNP) to control the mixing and preparation of the nanoscale polyelectrolyte complex. With RFNP, homogeneous mixing complexation between oppositely charged chitosan derivatives could be achieved, resulting in stable nanoscale complexes (NCs) with controllable size and narrow size distribution. The smallest size of NCs is found at specific pH due to the maximum attraction of positive and negative molecules of chitosan. The size can be modulated by altering the volumetric flow rates of inlet streams, concentration, and charge molar ratio of two oppositely charged chitosan derivatives. The charge molar ratio is also tuned to create NCs with positive and negative shells. There is no significant variation in the size of NCs produced at different intervals of time. This method allows continuous and tunable NC production and could have the potential for fast, practical translation.

Controlled Release of Chlorogenic Acid from Polyvinyl Alcohol/Poly(γ-Glutamic Acid) Blended Electrospun Nanofiber Mats with Potential Applications in Diabetic Foot Treatment

This work biosynthesized poly(γ-glutamic acid) (γ-PGA) produced by Bacillus licheniformis ATCC-9945a. This material was utilized to prepare electrospun nanofibers with solutions of 10% polyvinyl alcohol (PVA) (w/v) mixed with γ-PGA at 5 and 10% w/v, intended as a wound dressing for diabetic foot treatment. These solutions were loaded with chlorogenic acid (CGA), an active hypoglycemic agent. Morphological analysis showed a decrease in size of the fibers with the combination of PVA/γ-PGA compared to pure PVA nanofibers, which was attributed to the hydrogen bonding interactions between the glutaraldehyde vapors, γ-PGA, and PVA that permitted nanofiber cross-linking and allowed CGA release. The in vitro release analysis showed that the PVA membranes reached 28% delivery after the first 24 h. Notably, the nanofiber mat with PVA blended with 5% γ-PGA reached 57% delivery, and the PVA nanofiber with 10% γ-PGA reached 66% release after the same amount of time. The rate constant for the release kinetics showed that PVA with 5% γ-PGA had a higher value than that of the other samples, reaching saturation first.

Drug delivery applications of poly-γ-glutamic acid

Background

Poly-γ-glutamic acid (γ-PGA) is a biopolymer of microbial origin, consisting of repeating units of l-glutamic acid and/or D-glutamic acid. The biopolymer has found use in the fields of agriculture, food, wastewater, and medicine, owing to its non-toxic, biodegradable, and biocompatible properties. Due to its biodegradability, γ-PGA is being tipped to dislodge synthetic plastics in drug delivery application. High cost of production, relative to plastics, is however a clog in the wheel of achieving this.

Main body of abstract

This review looked at the production, nanoparticles fabrication, and drug delivery application of γ-PGA. γ-PGA production optimization by modifying the fermentation medium to tailor towards the production of desirable polymer at reduced cost and techniques for the formulation of γ-PGA nanoparticle as well as its characterization were discussed. This review also evaluated the application of γ-PGA and its nanoparticles in the delivery of drugs to action site. Characterization of γ-PGA and its nanoparticles is a crucial step towards determining the applicability of the biopolymer. γ-PGA has been used in the delivery of active agents to action sites.

Conclusion

This review highlights some of the efforts that have been made in the appraisal of γ-PGA and its nanoparticles for drug delivery. γ-PGA is a candidate for future extensive use in drug delivery.

NANO-BIOTECHNOLOGY AND ITS INNOVATIVE PERSPECTIVE IN DIABETES MANAGEMENT

Diabetes occurs due to the imbalance of glucose in the body known as glucose homeostasis, thus leading to metabolic changes in the body. The two stages hypoglycemia or hyperglycemia classify diabetes into various categories. Various bio-nanotechnological approaches are coupled up with nano particulates, polymers, liposome, various gold plated and solid lipid particulates, regulating transcellular transport, non specific cellular uptake, and paracellular transport, leading to oral, trans-dermal , pulmonary, buccal , nasal , specific gene oriented administration to avoid the patient's non compliance with the parental routes of administration. Phytochemicals are emerging strategies for the future prospects of diabetes management.

Nanochitosan: Commemorating the Metamorphosis of an ExoSkeletal Waste to a Versatile Nutraceutical

Chitin (poly-N-acetyl-D-glucosamine) is the second (after cellulose) most abundant organic polymer. In its deacetylated form-chitosan-becomes a very interesting material for medical use. The chitosan nano-structures whose preparation is described in this article shows unique biomedical value. The preparation of nanochitosan, as well as the most vital biomedical applications (antitumor, drug delivery and other medical uses), have been discussed in this review. The challenges confronting the progress of nanochitosan from benchtop to bedside clinical settings have been evaluated. The need for inclusion of nano aspects into chitosan research, with improvisation from nanotechnological inputs has been prescribed for breaking down the limitations. Future perspectives of nanochitosan and the challenges facing nanochitosan applications and the areas needing research focus have been highlighted.

Poly-γ-glutamic acid derived nanopolyplexes for up-regulation of gamma-glutamyl transpeptidase to augment tumor active targeting and enhance synergistic antitumor therapy by regulating intracellular redox homeostasis

The active targeting strategy has achieved inspiring progress for drug accumulation in tumor therapy; however, the insufficient expression level of many potential receptors poses challenges for drug delivery. Poly-γ-glutamic acid (γ-pGluA), a naturally occurring anionic biopolymer, showed high affinity with tumor-associated gamma-glutamyl transpeptidase (GGT), which localized on the cell surface and exhibited intracellular redox homeostasis-dependent expression pattern; thus, GGT was utilized for mediating endocytosis of nanoparticles. Herein, GGT-targeting nanopolyplexes (γ-pGluA-CSO@Fe³⁺, PCFN) consisting of cationic chitosan and GGT-targeting γ-pGluA blended with iron ion were constructed to load reactive oxygen species-induced menadione (MA) and doxorubicin, which were utilized to investigate the mechanism of GGT up-regulation. Briefly, the pretreated PCFN/MA induced an intracellular oxidative stress environment, which facilitated adjusted up-regulated GGT expression and boosted tumor targeting. Subsequently, the destroyed redox homeostasis sensitized tumors for synergistic therapy. The innovative strategy of augmenting active targeting by disturbing intracellular redox homeostasis offers insight for the application of γ-pGluA-derived nanopolyplexes.

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.

Biomedical and Pharmacological Uses of Fluorescein Isothiocyanate Chitosan-Based Nanocarriers

Chitosan-based nanocarriers (ChNCs) are considered suitable drug carriers due to their ability to encapsulate a variety of drugs and cross biological barriers to deliver the cargo to their target site. Fluorescein isothiocyanate-labeled chitosan-based NCs (FITC@ChNCs) are used extensively in biomedical and pharmacological applications. The main advantage of using FITC@ChNCs consists of the ability to track their fate both intra and extracellularly. This journey is strictly dependent on the physico-chemical properties of the carrier and the cell types under investigation. Other applications make use of fluorescent ChNCs in cell labeling for the detection of disorders in vivo and controlling of living cells in situ. This review describes the use of FITC@ChNCs in the various applications with a focus on understanding their usefulness in labeled drug-delivery systems.

Binary Solutions of Hyaluronan and Lactose-Modified Chitosan: The Influence of Experimental Variables in Assembling Complex Coacervates

A miscibility study between oppositely charged polyelectrolytes, namely hyaluronic acid and a lactose-modified chitosan, is here reported. Experimental variables such as polymers' weight ratios, pH values, ionic strengths and hyaluronic acid molecular weights were considered. Transmittance analyses demonstrated the mutual solubility of the two biopolymers at a neutral pH. The onset of the liquid-liquid phase separation due to electrostatic interactions between the two polymers was detected at pH 4.5, and it was found to be affected by the overall ionic strength, the modality of mixing and the polymers' weight ratio. Thorough Dynamic Light Scattering (DLS) measurements were performed to check the quality of the formed coacervates by investigating their dimensions, homogeneity and surface charge. The whole DLS results highlighted the influence of the hyaluronic acid molecular weight in affecting coacervates' dispersity and size.

Biodistribution and pharmacokinetics of thiolated chitosan nanoparticles for oral delivery of insulin in vivo

To improve the quality of life of diabetic patients, oral delivery of insulin would be better than subcutaneous injection, and the encapsulation of insulin for its oral delivery is a promising alternative one. In this study, we prepared an oral insulin delivery system using thiolated chitosan nanoparticles (TCNPs) loaded with insulin (Ins) and tested under in vitro and in vivo systems. TCNPs prepared from CS and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP) at 4:1 ratio showed 220 ± 4 nm, 2.3 ± 1 mV, and 119 ± 4 μmol g^-1 in their size, charge and sulfhydryl content, respectively. There was a sustained release of insulin from the TCNPs at pH 5.3. TCNPs treatment did not alter cell viability in vitro and oral administration of TCNPs reached over the tip of the microvilli near the intestinal mucosa in vivo. There were increased and decreased the levels of insulin and glucose in the blood, respectively when Ins-TCNPs were orally administered in the diabetes induced rats. Thus, our results suggested that the insulin stays significantly for a prolonged period to make bio-distribution and bioavailability due to its interaction with the mucus of the intestine, thus offering a better oral insulin delivery system for diabetic patients.

Mesoscale Simulations of pH-Responsive Amphiphilic Polymeric Micelles for Oral Drug Delivery

It is of great significance to study the structure property and self-assembly of amphiphilic block copolymer in order to effectively and efficiently design and prepare drug delivery systems. In this work, dissipative particle dynamics (DPD) simulation method was used to investigate the structure property and self-assembly ability of pH-responsive amphiphilic block copolymer poly(methyl methacrylate-co-methacrylic acid)-b-poly(aminoethyl methacrylate) (poly(MMA-co-MAA)-b-PAEMA). The effects of different block ratios (hydrophilic PAEMA segment and pH-sensitive PMAA segment) in copolymer on self-assembly and drug loading capacity including drug distribution were extensively investigated. The increase of hydrophilic PAEMA facilitated the formation of a typical core-shell structure as well as a hydrophobic PMAA segment. Furthermore, the optimal drug-carrier ratio was confirmed by an analysis of the drug distribution during the self-assembly process of block copolymer and model drug Ibuprofen (IBU). In addition, the drug distribution and nanostructure of IBU-loaded polymeric micelles (PMs) self-assembled from precise block copolymer (PMMA-b-PMAA-b-PAEMA) and block copolymer (poly(MMA-co-MAA)-b-PAEMA) with random pH-responsive/hydrophobic structure were evaluated, showing that almost all drug molecules were encapsulated into a core for a random copolymer compared to the analogue. The nanostructures of IBU-loaded PMs at different pH values were evaluated. The results displayed that the nanostructure was stable at pH < pK_a and anomalous at pH > pK_a which indicated drug release, suggesting that the PMs could be used in oral drug delivery. These findings proved that the amphiphilic block copolymer P(MMA₃₀-co-MAA₃₃)-b-PAEMA₃₈ with random structure and pH-sensitivity might be a potential drug carrier. Moreover, DPD simulation shows potential to study the structure property of PMs self-assembled from amphiphilic block copolymer.

Nanoparticle Delivery Systems in the Treatment of Diabetes Complications

Diabetes mellitus, an incurable metabolic disease, is characterized by changes in the homeostasis of blood sugar levels, being the subcutaneous injection of insulin the first line treatment. This administration route is however associated with limited patient's compliance, due to the risk of pain, discomfort and local infection. Nanoparticles have been proposed as insulin carriers to make possible the administration of the peptide via friendlier pathways without the need of injection, i.e., via oral or nasal routes. Nanoparticles stand for particles in the nanometer range that can be obtained from different materials (e.g., polysaccharides, synthetic polymers, lipid) and are commonly used with the aim to improve the physicochemical stability of the loaded drug and thereby its bioavailability. This review discusses the use of different types of nanoparticles (e.g., polymeric and lipid nanoparticles, liposomes, dendrimers, niosomes, micelles, nanoemulsions and also drug nanosuspensions) for improved delivery of different oral hypoglycemic agents in comparison to conventional therapies.

Dual-Action Pesticide Carrier That Continuously Induces Plant Resistance, Enhances Plant Anti-Tobacco Mosaic Virus Activity, and Promotes Plant Growth

Improving plant resistance against systemic diseases remains a challenging research topic. In this study, we developed a dual-action pesticide-loaded hydrogel with the capacity to significantly induce plant resistance against tobacco mosaic virus (TMV) infection and promote plant growth. We produced an alginate-lentinan-amino-oligosaccharide hydrogel (ALA-hydrogel) by coating the surface of an alginate-lentinan drug-loaded hydrogel (AL-hydrogel) with amino-oligosaccharide using electrostatic action. We determined the formation of the amino-oligosaccharide film using various approaches, including Fourier transform infrared spectrometry, the ζ potential test, scanning electron microscopy, and elemental analysis. It was found that the ALA-hydrogel exhibited stable sustained-release activity, and the release time was significantly longer than that of the AL-hydrogel. In addition, we demonstrated that the ALA-hydrogel was able to continuously and strongly induce plant resistance against TMV and increase the release of calcium ions to promote Nicotiana benthamiana growth. Meanwhile, the ALA-hydrogel maintained an extremely high safety to organisms. Our findings provide an alternative to the traditional approach of applying pesticide for controlling plant viral diseases. In the future, this hydrogel with the simple synthesis method, green synthetic materials, and its efficiency in the induction of plant resistance will attract increasing attention and have good potential to be employed in plant protection and agricultural production.

Polymer-Based Nanoparticle Strategies for Insulin Delivery

Diabetes mellitus (DM) is a chronic metabolic illness estimated to have affected 451 million individuals to date, with this number expected to significantly rise in the coming years. There are two main classes of this disease, namely type 1 diabetes (T1D) and type 2 diabetes (T2D). Insulin therapy is pivotal in the management of diabetes, with diabetic individuals taking multiple daily insulin injections. However, the mode of administration has numerous drawbacks, resulting in poor patient compliance. In order to optimize insulin therapy, novel drug delivery systems (DDSes) have been suggested, and alternative routes of administration have been investigated. A novel aspect in the field of drug delivery was brought about by the coalescence of polymeric science and nanotechnology. In addition to polymeric nanoparticles (PNPs), insulin DDSes can incorporate the use of nanoplatforms/carriers. A combination of these systems can bring about novel formulations and lead to significant improvements in the drug delivery system (DDS) with regard to therapeutic efficacy, bioavailability, increased half-life, improved transport through physical and chemical barriers, and controlled drug delivery. This review will discuss how recent developments in polymer chemistry and nanotechnology have been employed in a multitude of platforms as well as in administration routes for the safe and efficient delivery of insulin for the treatment of DM.

pH-Responsive Polypeptide-Based Smart Nano-Carriers for Theranostic Applications

Smart nano-carriers have attained great significance in the biomedical field due to their versatile and interesting designs with different functionalities. The initial stages of the development of nanocarriers mainly focused on the guest loading efficiency, biocompatibility of the host and the circulation time. Later the requirements of less side effects with more efficacy arose by attributing targetability and stimuli-responsive characteristics to nano-carriers along with their bio- compatibility. Researchers are utilizing many stimuli-responsive polymers for the better release of the guest molecules at the targeted sites. Among these, pH-triggered release achieves increasing importance because of the pH variation in different organ and cancer cells of acidic pH. This specific feature is utilized to release the guest molecules more precisely in the targeted site by designing polymers having specific functionality with the pH dependent morphology change characteristics. In this review, we mainly concert on the pH-responsive polypeptides and some interesting nano-carrier designs for the effective theranostic applications. Also, emphasis is made on pharmaceutical application of the different nano-carriers with respect to the organ, tissue and cellular level pH environment.

Chitosan/sodium tripolyphosphate nanoparticles as efficient vehicles for enhancing the cellular uptake of fish-derived peptide

Methodology to enhance the intestinal absorption of peptides is an important challenge due to their easily degradation and poor permeability across the intestinal epithelium. In this study, the fish-derived peptide (DGDDGEAGKIG)-loaded chitosan (CS) nanoparticles (CS/PEP-NPs) were prepared and investigated in Caco-2 monolayer model. The results indicated zeta potential of CS/PEP-NPs increased with the increase in molecular weight of CS (10-50 kDa). Transmission electron microscopy images revealed the CS/PEP-NPs were uniform spherical-shaped nanoparticles with a diameter of 50-200 nm (150 kDa). Compared to other CS/PEP-NPs, 150-kDa CS/PEP-NPs performed an outstanding apparent permeability coefficient (Papp, 2.29 × 10^-5  cm s^-1 ) and cumulative amount of peptide (120 min, 2,987 ng) in Caco-2 cells. CS/PEP-NPs could reduce the tight junction integrity of Caco-2 cells and enhance the intracellular fluorescence intensities of fluorescein isothiocyanate-labeled peptide. These findings suggest that chitosan nanoparticles are promising carriers to promote intestinal absorption of fish-derived peptide via paracellular pathway mediated by tight junctions. PRACTICAL APPLICATIONS: Chitosans are promising carriers to promote intestinal absorption of fish-derived peptide. The 150-kDa CS/PEP-NPs performed an outstanding apparent permeability coefficient (Papp, 2.29 × 10^-5  cm s^-1 ) and cumulative amount of peptide (120 min, 2,987 ng) in Caco-2 cells. CS/PEP-NPs could reduce the tight junction integrity of Caco-2 cells and enhance the peptide uptake by paracellular pathway. Chitosan nanoparticles can be developed as vehicles for enhancing the cellular uptake of peptide in food industry.

Encapsulation of Cinnamaldehyde using Chitosan: Stability, Mucoadhesive and Cinnamaldehyde Release

Cinnamaldehyde contained in cinnamon oil is useful as an antidiabetic; however, it has very low oral bioavailability. One effort to increase oral bioavailability of cinnamaldehyde is by encapsulation using chitosan. Encapsulation of cinnamaldehyde in chitosan has been successfully made in the form of powder. The aim of this study was to obtain data of stability, mucoadhesive and cinnamaldehyde release from cinnamaldehyde encapsulated chitosan. Stability tests were performed physically and chemically. Mucoadhesive tests were carried out in vitro in two steps, which were granule fabrication and then mucoadhesive test. The results showed that the levels of cinnamaldehyde decreased within 4 weeks, from the first to the fourth week 100%; 99.87%; 98.85%; 97.33%, respectively. Cinnamaldehyde powder did not change significantly in specific gravity, pH, centrifugation and organoleptic after a month. The release precentage of cinnamaldehyde in acidic media pH 1.2 for 180 minutes was 83.4%, whereas in alkaline media pH 7.4 for 360 minutes was 61%. The cinnamaldehyde encapsulated chitosan nanoparticle powder performed mucoadhesive capacity in the gastric mucosa and in the intestinal mucosa of 91.5% and 84.61%, respectively.

Challenges in oral peptide delivery: lessons learnt from the clinic and future prospects

Therapeutic peptides have become very successful drugs due to their specificity, potency and low toxicity, but they show challenges for their delivery, due to their short half-life and rapid plasma clearance. For these reasons, peptides are usually administered using injectable sustained-release formulations. Oral peptide route is highly compelling from a patient and commercial point of view. However, poor peptide stability and low permeability across the intestinal epithelium still make it very challenging to effectively deliver peptides by the oral route. In this paper, biopharmaceutical and formulation features of oral peptides, as well as key clinical outcomes, are reviewed and discussed in the perspective of designing next generation of oral peptide formulations for a true paradigm shift.

Chitosan Based Self-Assembled Nanoparticles in Drug Delivery

Chitosan is a cationic polysaccharide that is usually obtained by alkaline deacetylation of chitin poly(N-acetylglucosamine). It is biocompatible, biodegradable, mucoadhesive, and non-toxic. These excellent biological properties make chitosan a good candidate for a platform in developing drug delivery systems having improved biodistribution, increased specificity and sensitivity, and reduced pharmacological toxicity. In particular, chitosan nanoparticles are found to be appropriate for non-invasive routes of drug administration: oral, nasal, pulmonary and ocular routes. These applications are facilitated by the absorption-enhancing effect of chitosan. Many procedures for obtaining chitosan nanoparticles have been proposed. Particularly, the introduction of hydrophobic moieties into chitosan molecules by grafting to generate a hydrophobic-hydrophilic balance promoting self-assembly is a current and appealing approach. The grafting agent can be a hydrophobic moiety forming micelles that can entrap lipophilic drugs or it can be the drug itself. Another suitable way to generate self-assembled chitosan nanoparticles is through the formation of polyelectrolyte complexes with polyanions. This paper reviews the main approaches for preparing chitosan nanoparticles by self-assembly through both procedures, and illustrates the state of the art of their application in drug delivery.

Scalable production of core-shell nanoparticles by flash nanocomplexation to enhance mucosal transport for oral delivery of insulin

Scalable manufacturing continues to present a major barrier for clinical translation of nanotherapeutics. Methods available for fabricating protein-encapsulating nanoparticles in a scalable fashion are scarce. Protein delivery often requires multiple functionalities to be incorporated into the same vehicle. Specifically for nanoparticle-mediated oral delivery of protein therapeutics, protection in GI tract, site-specific release, facilitating transmucosal permeation, and enhancing epithelial transport are a few desirable features to be engineered into a nanoparticle system. Here we devised a sequential flash nanocomplexation (FNC) technique for the scalable production of a core-shell structured nanoparticle system by combining materials choice and particle size and structure to fulfill these functions, therefore enhancing the delivery efficiency of insulin. This method is highly effective in controlling the size, generating core-shell structure with high encapsulation efficiency (97%) and payload capacity (67%) using insulin/l-penetratin complex nanoparticles as a core coated with hyaluronic acid (HA). Both the in vitro and in vivo models confirmed that the HA coating on these core-shell nanoparticles enhanced the permeation of nanoparticles through the intestinal mucus layer and improved trans-epithelial absorption of insulin nanoparticles; and the enhancement effect was most prominent using HA with the highest average molecular weight. The insulin-loaded nanoparticles were then encapsulated into enteric microcapsules (MCs) in an FNC process to provide additional protection against the acidic environment in the stomach while allowing rapid release of insulin nanoparticles when they reach small intestine. The optimized multifunctional MCs delivered an effective glucose reduction in a Type I diabetes rat model following a single oral administration, yielding a relative bioavailability of 11% in comparison with subcutaneous injection of free-form insulin. This FNC technique is highly effective in controlling particle size and structure to improve delivery properties and function. It can be easily extended to oral delivery for other protein therapeutics.

Insulin Inclusion into a Tragacanth Hydrogel: An Oral Delivery System for Insulin

Nanoparticles or microparticles created by physical complexation between two polyelectrolytes may have a prospective use as an excipient for oral insulin administration. Natural polymers such as tragacanth, alginate, dextran, pullulan, hyaluronic acid, gelatin and chitosan can be potential candidates for this purpose. In this research, insulin particles were prepared by the inclusion of insulin into a tragacanth hydrogel. The effect of the pH and concentration relationship involving polyelectrolytes offering individual particle size and zeta potential was assessed by zetasizer and scanning electron microscopy (SEM). Insulin-tragacanth interactions at varying pH (3.7, 4.3, 4.6, or 6), and concentration (0.1%, 0.5%, or 1% w/w) were evaluated by differential scanning calorimetry (DSC) and ATR Fourier transform infrared (ATR-FTIR) analysis. Individual and smaller particles, approximately 800 nm, were acquired at pH 4.6 with 0.5% of tragacanth. The acid gelation test indicated that insulin could be entrapped in the physical hydrogel of tragacanth. DSC thermograms of insulin-tragacanth showed shifts on the same unloaded tragacanth peaks and suggested polyelectrolyte-protein interactions at a pH close to 4.3-4.6. FTIR spectra of tragacanth-insulin complexes exhibited amide absorption bands featuring in the protein spectra and revealed the creation of a new chemical substance.

pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms

Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines. This review provides a wide perspective on current status of pH-responsive oral drug delivery systems prepared mainly with organic polymers or inorganic materials, including the strategies used to overcome GI barriers, the challenges in their development and future prospects, with focus on technology trends to improve the bioavailability of orally delivered drugs, the mechanisms of drug release from pH-responsive oral formulations, and their application for drug delivery, such as protein and peptide therapeutics, vaccination, inflammatory bowel disease (IBD) and bacterial infections.