Entrapment enhancement of peptide drugs in niosomes

The crossroad of nanovesicles and oral delivery of insulin

INTRODUCTION

Diabetes mellitus is one of the challenging health problems worldwide. Multiple daily subcutaneous injection of insulin causes poor compliance in patients. Development of efficient oral formulations to improve the quality of life of such patients has been an important goal in pharmaceutical industry. However, due to serious issues such as low bioavailability and instability, it has not been achieved yet.

AREAS COVERED

Due to functional properties of the vesicles and the fact that hepatic-directed vesicles of insulin could reach the clinical phases, we focused on three main vesicular delivery systems for oral delivery of insulin: liposomes, niosomes, and polymersomes. Recent papers were thoroughly discussed to provide a broad overview of such oral delivery systems.

EXPERT OPINION

Although conventional liposomes are unstable in the presence of bile salts, their further modifications such as surface coating could increase their stability in the GI tract. Bilosomes showed good flexibility and stability in GI fluids. Also, niosomes were stable, but they could not induce significant hypoglycemia in animal studies. Although polymersomes were effective, they are expensive and there are some issues about their safety and industrial scale-up. Also, we believe that other modifications such as addition of a targeting agent or surface coating of the vesicles could significantly increase the bioavailability of insulin-loaded vesicles.

Niosomes: a novel targeted drug delivery system for cancer

Recently, nanotechnology is involved in various fields of science, of which medicine is one of the most obvious. The use of nanoparticles in the process of treating and diagnosing diseases has created a novel way of therapeutic strategies with effective mechanisms of action. Also, due to the remarkable progress of personalized medicine, the effort is to reduce the side effects of treatment paths as much as possible and to provide targeted treatments. Therefore, the targeted delivery of drugs is important in different diseases, especially in patients who receive combined drugs, because the delivery of different drug structures requires different systems so that there is no change in the drug and its effectiveness. Niosomes are polymeric nanoparticles that show favorable characteristics in drug delivery. In addition to biocompatibility and high absorption, these nanoparticles also provide the possibility of reducing the drug dosage and targeting the release of drugs, as well as the delivery of both hydrophilic and lipophilic drugs by Niosome vesicles. Since various factors such as components, preparation, and optimization methods are effective in the size and formation of niosomal structures, in this review, the characteristics related to niosome vesicles were first examined and then the in silico tools for designing, prediction, and optimization were explained. Finally, anticancer drugs delivered by niosomes were compared and discussed to be a suitable model for designing therapeutic strategies. In this research, it has been tried to examine all the aspects required for drug delivery engineering using niosomes and finally, by presenting clinical examples of the use of these nanocarriers in cancer, its clinical characteristics were also expressed.

A state-of-the-art review on the recent advances of niosomes as a targeted drug delivery system

The buildup of nonionic surfactants in the aqueous environment produces niosomes. The usage of niosomes is becoming increasingly frequent due to their sustainability, low cost of components and assembly, large-scale manufacture, and, finally, easy maintenance of the niosomes to the other. Because of their nonionic characteristics, niosomes play a critical role in medication delivery systems. Controlled release and targeted distribution of niosomes to treat cancer, infectious illnesses, and other disorders are one of their most important properties. Niosomes can also be injected by ocular and transdermal routes, which are less common than oral and parenteral administration. Using niosomes to manufacture biotechnology goods and novel vaccines is one of the most exciting research fields today. The molecular structure of niosomes, the physicochemical characteristics of nonionic surfactants in their formulation, the influence of external stimuli on niosomes, the many methods of niosomes administration, and their diverse therapeutic qualities are all explored in this study.

Anti-ageing peptides and proteins for topical applications: a review

Skin ageing is a cumulative result of oxidative stress, predominantly caused by reactive oxygen species (ROS). Respiration, pollutants, toxins, or ultraviolet A (UVA) irradiation produce ROS with 80% of skin damage attributed to UVA irradiation. Anti-ageing peptides and proteins are considered valuable compounds for removing ROS to prevent skin ageing and maintenance of skin health. In this review, skin ageing theory has been illustrated with a focus on the mechanism and relationship with anti-ageing peptides and proteins. The effects, classification, and transport pathways of anti-ageing peptides and proteins across skin are summarized and discussed. Over the last decade, several novel formulations and advanced strategies have been developed to overcome the challenges in the dermal delivery of proteins and peptides for skin ageing. This article also provides an in-depth review of the latest advancements in the dermal delivery of anti-ageing proteins and peptides. Based on these studies, this review prospected several semi-solid dosage forms to achieve topical applicability for anti-ageing peptides and proteins.

Synergistic Anti-Staphylococcal Activity Of Niosomal Recombinant Lysostaphin-LL-37

Purpose

Staphylococcus aureus is the most common persistent pathogen in humans, so development of new formulations to combat pathogen invasion is quite necessary.

Methods

In the current study, for the first time, the synergistic activity of recombinant lysostaphin and LL-37 peptide was studied against S. aureus. Moreover, different niosomal formulations of the peptide and protein were prepared and analyzed in terms of size, shape, zeta potential, and entrapment efficiency. Also, a long-term antibacterial activity of the best niosomal formulation and free forms was measured against S. aureus in vitro.

Results

The optimal niosomal formulation was obtained by mixing the surfactants (span60 and tween60; 2:1 w/w), cholesterol, and dicetylphosphate at a ratio of 47:47:6, respectively. They showed uniform spherical shapes with the size of 565 and 325 nm for lysostaphin and LL-37, respectively. This formulation showed high entrapment efficiency for the peptide, protein, and a slow-release profile over time. Release kinetic was best fitted by Higuchi model indicating a diffusion-based release of the drugs. The lysostaphin/LL-37 niosomal formulation synergistically inhibited growth of S. aureus for up to 72 hours. However, the same amounts of free forms of both anti-microbial agents could not hold the anti-microbial effect and growth was seen in the following 72 hours. Cytotoxicity assay specified that lysostaphin/LL-37 niosomal combination had no deleterious effect on normal fibroblast cells at effective antimicrobial concentrations.

Conclusion

This study indicated that the use of lysostaphin in combination with LL-37, either in niosomal or free forms, synergistically inhibited growth of S. aureus in vitro. In addition, niosomal preparation of antimicrobial agents could provide a long-term protection against bacterial infections.

Nanogel loaded with surfactant based nanovesicles for enhanced ocular delivery of acetazolamide

Objective: Intraocular pressure has always been a great challenge for topical ophthalmic drugs. The study aimed to develop ocular surfactant based nanovesicles (NVs) carried in mucoadhesive nanogel providing efficient topical delivery of acetazolamide (ACZ). Methods: For the sake of optimizing formulation parameters, the effect of the type of edge activator and its ratio to sorbitan monostearate (Span 60) on the mean particle size, entrapment efficiency (%EE), and zeta potential (ZP) of produced NVs was investigated. Results: The selected formulation composed of Span 60:sodium deoxycholate with ratio 80:20 showed an average diameter of 202.90 nm, %EE of 90.2%, and ZP of -38.1 mV with a spherical and smooth surface. The ACZ loaded nanovesicles (ACZ-NVs) were embedded in different concentrations of Chitosan-sodium tripolyphosphate (CS-TPP) nanogels. The nanogel prepared using 1.5% CS showed the most promising viscosity, adhesion time, and rheological behavior (118,246 cP, 290 min, and thixotropic behavior, respectively). The in vitro release of ACZ showed a controlled release profile after incorporation in nanogels. The in vivo irritation test showed minimal irritation for the nanogel formulation compared to ACZ topical suspension. The effect of intraocular pressure lowering was significantly prolonged using ACZ-NV nanogels compared to ACZ oral tablets. Histopathological examination emphasized the healing power of CS on retinal atrophy. Conclusion: The research work indicated a promising potential for successful topical delivery of ACZ.

Improvements in chemical carriers of proteins and peptides

The successful intracellular delivery of biologically active proteins and peptides plays an important role for therapeutic applications. Indeed, protein/peptide delivery could overcome some problems of gene therapy, for example, controlling the expression levels and the integration of transgene into the host cell genome. Thus, protein/peptide drug delivery showed a promising and safe approach for treatment of cancer and infectious diseases. Due to the unique physical and chemical properties of proteins, their production (e.g., isolation, purification & formulation) and delivery represented significant challenges in pharmaceutical studies. Modification in the structural moieties of these protein/peptide drugs could improve their solubility, stability, crystallinity, lipophilicity, enzymatic susceptibility and targetability, and subsequently, therapies and cures against various diseases. Using the structural modification of protein/peptide, their delivery provided overall higher success rates including high specificity, high activity, bioreactivity and safety. Recently, biotechnological and pharmaceutical companies have tried to find novel techniques for the modifications and improve delivery systems/carriers. However, each carrier has its own benefits and drawbacks, and an appropriate carrier is often established by the physicochemical properties of protein or peptide, the ideal route of injection, and clinical characteristics of therapy. In this review, an attempt was made to give an overview on the chemical carriers for proteins and peptides as well as the recent advances in this field.

Bioadhesive Chitosan-Coated Cationic Nanoliposomes With Improved Insulin Encapsulation and Prolonged Oral Hypoglycemic Effect in Diabetic Mice

Oral administration of insulin is hampered by the lack of carriers that can efficiently achieve high encapsulation, avoid gastric degradation, overcome mucosal barriers, and prolong the hypoglycemic effect. Chitosan (CS)-coated insulin-loaded cationic liposomes have been developed and optimized for improved oral delivery. Liposomes were prepared cationic to improve insulin encapsulation. CS was selected as a mucoadhesive coat to prolong the system's residence and absorption. The performance of CS-coated liposomes compared with uncoated liposomes was examined in vitro, ex vivo, and in vivo in streptozotocin-induced diabetic mice. Free uncoated liposomes showed high positive zeta potential of +58.8 ± 2.2 mV that reduced (+29.9 ± 1.4 mV) after insulin encapsulation, confirming the obtained high entrapment efficiency of 87.5 ± 0.6%. CS-coated liposomes showed nanosize of 439.0 ± 12.3 nm and zeta potential of +60.5 ± 1.9 mV. In vitro insulin release was limited to 18.9 ± 0.35% in simulated gastric fluid, whereas in simulated intestinal fluid, 73.33 ± 0.68% was released after 48 h from CS-coated liposomes. Ex vivo intestinal mucoadhesion showed increased tissue residence of CS-coated liposomes compared with uncoated liposomes. A striking reduction in the glucose level was observed 1 h after oral administration of CS-coated liposomes and maintained up to 8 h (p <0.01 vs. insulin solution or uncoated liposomes) within the normal value 129.29 ± 3.15 mg/dL. In conclusion, CS-coated insulin-loaded cationic liposomes improved loading efficiency with promising prolonged pharmacological effect.

Nanotechnology based approaches for anti-diabetic drugs delivery

Nanotechnology science has been diverged its application in several fields with the advantages to operate with nanometric range of objects. Emerging field of nanotechnology has been also being approached and applied in medical biology for improved efficacy and safety. Increased success in therapeutic field has focused several approaches in the treatment of the common metabolic disorder, diabetes. The development of nanocarriers for improved delivery of different oral hypoglycemic agents compared to conventional therapies includes nanoparticles (NPs), liposomes, dendrimer, niosomes and micelles, which produces great control over the increased blood glucose level and thus becoming an eye catching and most promising technology now-a-days. Besides, embellishment of nanocarriers with several ligands makes it more targeted delivery with the protection of entrapped hypoglycaemic agents against degradation, thereby optimizing prolonged blood glucose lowering effect. Thus, nanocarriers of hypoglycemic agents provide the aim towards improved diabetes management with minimized risk of acute and chronic complications. In this review, we provide an overview on distinctive features of each nano-based drug delivery system for diabetic treatment and current NPs applications in diabetes management.

Non-Ionic Surfactant Vesicles (Niosomes) as New Drug Delivery Systems

Lipid vesicular systems composed of hydrated amphihiles with or without bilayer inducing agents such as cholesterol. On the basis of used amphiphilic molecule different nomenclature are used as liposomes, ufasomes and niosomes. Nonionic surfactants with mono-, di- or trialkyl chains form niosomes which are lipid vesicles with more chemical stability in comparison with phospholipids of liposomes. Both hydrophobic and hydrophilic chemicals can be encapsulated in niosomes as a new drug delivery system. This drug carrier system could have administered via injection, oral, pulmonary, vaginal, rectal, ophthalmic, nasal or transdermal routes with penetration enhancing potential. This chapter presents a detailed explain about niosome forming components, methods of preparation and routes of administration. Many examples for drug delivery potential of niosomes are also available in this review. Vaccine adjuvant and genetic substances vector capabilities are not given here.

Non-Ionic Surfactant Vesicles (Niosomes) as New Drug Delivery Systems

Lipid vesicular systems composed of hydrated amphihiles with or without bilayer inducing agents such as cholesterol. On the basis of used amphiphilic molecule different nomenclature are used as liposomes, ufasomes and niosomes. Nonionic surfactants with mono-, di- or trialkyl chains form niosomes which are lipid vesicles with more chemical stability in comparison with phospholipids of liposomes. Both hydrophobic and hydrophilic chemicals can be encapsulated in niosomes as a new drug delivery system. This drug carrier system could have administered via injection, oral, pulmonary, vaginal, rectal, ophthalmic, nasal or transdermal routes with penetration enhancing potential. This chapter presents a detailed explain about niosome forming components, methods of preparation and routes of administration. Many examples for drug delivery potential of niosomes are also available in this review. Vaccine adjuvant and genetic substances vector capabilities are not given here.

Sodium dodecyl sulfate/β-cyclodextrin vesicles embedded in chitosan gel for insulin delivery with pH-selective release

In an answer to the challenge of enzymatic instability and low oral bioavailability of proteins/peptides, a new type of drug-delivery vesicle has been developed. The preparation, based on sodium dodecyl sulfate (SDS) and β-cyclodextrin (β-CD) embedded in chitosan gel, was used to successfully deliver the model drug-insulin. The self-assembled SDS/β-CD vesicles were prepared and characterized by particle size, zeta potential, appearance, microscopic morphology and entrapment efficiency. In addition, both the interaction of insulin with vesicles and the stability of insulin loaded in vesicles in the presence of pepsin were investigated. The vesicles were crosslinked into thermo-sensitive chitosan/β-glycerol phosphate solution for an in-situ gel to enhance the dilution stability. The in vitro release characteristics of insulin from gels in media at different pH values were investigated. The insulin loaded vesicles–chitosan hydrogel (IVG) improved the dilution stability of the vesicles and provided pH-selective sustained release compared with insulin solution–chitosan hydrogel (ISG). In vitro, IVG exhibited slow release in acidic solution and relatively quick release in neutral solutions to provide drug efficacy. In simulated digestive fluid, IVG showed better sustained release and insulin protection properties compared with ISG. Thus IVG might improve the stability of insulin during its transport in vivo and contribute to the bioavailability and therapeutic effect of insulin.

Nonionic surfactant vesicles for delivery of RNAi therapeutics

RNAi is a promising potential therapeutic approach for many diseases. A major barrier to its clinical translation is the lack of efficient delivery systems for siRNA. Among nonviral vectors, nonionic surfactant vesicles (niosomes) have shown a great deal of promise in terms of their efficacy and toxicity profiles. Nonionic surfactants have been shown to be a superior alternative to phospholipids in several studies. There is a large selection of surfactants with various properties that have been incorporated into niosomes. Therefore, there is great potential for innovation in terms of nisome composition. This article summarizes recent advancements in niosome technology for the delivery of siRNA.