Development and characterization of lipid-polymeric nanoparticles for oral insulin delivery

Introduction: The oral route is widely accepted as the most physiological path for exogenous administration of insulin, as it closely mimic the endogenous insulin pathway. Thus, in this work it is proposed an innovative lipid-polymeric nanocarrier to delivery insulin orally.

Areas covered: Nanoparticles were produced through a modified solvent emulsification-evaporation method, using ethyl palmitate and hydroxypropylmethylcellulose acetate succinate as matrix. Lipid-polymeric nanoparticles were around 300 nm in size, negatively charged (?20 mV) and associated insulin with efficiency higher than 80%. Differential scanning calorimetry suggested thermal stability of nanoparticles. In vitro release assays under simulated gastrointestinal conditions resulted in 9% and 14% of insulin released at pH 1.2 during 2 h and at pH 6.8 for 6 h, respectively, demonstrating the ability of those nanoparticles to protect insulin against premature degradation. Importantly, nanoparticles were observed to be safe at potential therapeutic concentrations as did not originate cytotoxicity to intestinal epithelial cells. Lastly, the permeability of nanoencapsulated insulin through Caco-2 monolayers and a triple Caco-2/HT29-MTX/Raji B cell model correlated well with slow release kinetics, and fosters the effectiveness of nanoparticles to promote intestinal absorption of peptidic drugs.

Expert opinion: Lipid-polymeric nanoparticles were developed to encapsulate and carry insulin through intestine. Overall, nanoparticles provide insulin stability and intestinal permeability.     

Hybrid nanoparticles for the topical delivery of norfloxacin for the effective treatment of bacterial infection produced after burn

The present study was designed to investigate the solubility and penetrability of norfloxacin after the topical application of developed lipid–polymer hybrid nanoparticle (LPN) formulation. The core shell of the LPNs formulation was composed of poly (lactic-co-glycolic acid) that is highly lipophilic in nature, thus control the release of drug. The developed formulations were characterised for size, shape (transmission electron microscopy [TEM], scanning electron microscopy [SEM], and atomic force microscopy), entrapment efficiency, Fourier transform infra-red (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). Moreover, in vitro skin permeation studies were performed to determine release profile of the drug. Norfloxacin loaded nanoparticles retained there antimicrobial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa. Stability study was suggested that the suitable storage condition should be at 4?±?2?°C/60?±?5% RH for the LPNs. Therefore, these nanoparticles showed a safe and effective long-lasting approach for long treatment of bacterial infections due to burn.     

Supercritical fluid technology for enhanced drug delivery

The rapid advances in the development of formulation and delivery systems based on micron-sized and nanoscale drug particles will create significant benefits to the pharmaceutical industry. Complementary to traditional methods, supercritical fluid techniques have found many useful, and sometimes unique, applications in the production and processing of drug particles. In this article background information is provided on a variety of supercritical fluid techniques relevant to drug formulation and delivery, recent advances and novel applications are highlighted, and the successful development of a new supercritical fluid rapid expansion technique for producing exclusively nanoscale drug particles will be discussed. Challenges and opportunities for further development and future applications are also reviewed.     

Use of nanoscale delivery systems to maintain synergistic drug ratios in vivo

Importance of the field: Drug combinations have been the standard of care in the treatment of cancer for > 50 years. Typically, combination chemotherapy uses agents with non-overlapping toxicities which are escalated to their maximum tolerated dose. However, emerging evidence indicates that this approach may not be providing optimal efficacy depending on the drug ratios to which the tumor is exposed. Combined drugs can be synergistic whereas other ratios of the same agents may be antagonistic or additive.

Areas covered in this review: In this review, we examine the importance of drug ratios in cancer therapy. We describe how manipulation of the lipid membrane and internal buffer composition maintains synergistic ratios of irinotecan and floxuridine (CPX-1), daunorubicin and cytarabine (CPX-351) or cisplatin and irinotecan (CPX-571). For polymer-based nanoparticles, prodrug hydrophobicity was exploited to coordinate the release of gemcitabine and the more hydrophobic paclitaxel. We present preclinical data for liposomal drug combinations which demonstrate that the most efficacious formulation is not always the highest dose of both agents.

What the reader will gain: An insight into the use of liposomes and polymer-based nanoparticles to deliver synergistic drug combinations to the tumor site and avoid antagonistic drug–drug interactions.

Take home message: The ability to control and maintain drug ratios in vivo through the use of nanoscale delivery vehicles results in a significant improvement in therapeutic activity.     

固体脂质纳米粒和纳米结构脂质载体在经皮给药系统中的研究进展

目的介绍固体脂质纳米粒和纳米结构脂质载体在经皮给药系统中的应用与优势,为其开发利用提供参考。方法查阅国内外相关文献共30余篇,从固体脂质纳米粒和纳米结构脂质载体用于经皮给药系统的优势、药物在固体脂质纳米粒和纳米结构脂质载体中的分布形式及固体脂质纳米粒和纳米结构脂质载体在经皮给药领域中的应用等方面进行综述。结果固体脂质纳米粒和纳米结构脂质载体可以增强药物稳定性,能在皮肤表面产生包封效应,增加皮肤水合作用,具有药物靶向性。结论固体脂质纳米粒和纳米结构脂质载体是极有发展前景的新型经皮给药系统。     

Stimuli-responsive graphene-incorporated multifunctional chitosan for drug delivery applications: a review

Introduction: Recently, the use of chitosan (CS) in the drug delivery has reached an acceptable maturity. Graphene-based drug delivery is also increasing rapidly due to its unique physical, mechanical, chemical, and electrical properties. Therefore, the combination of CS and graphene can provide a promising carrier for the loading and controlled release of therapeutic agents.

Area covered: In this review, we will outline the advantages of this new drug delivery system (DDS) in association with CS and graphene alone and will list the various forms of these carriers, which have been studied in recent years as DDSs. Finally, we will discuss the application of this hybrid composite in other fields.

Expert opinion: The introducing the GO amends the mechanical characteristics of CS, which is a major problem in the use of CS-based carriers in drug delivery due to burst release in a CS-based controlled release system through the poor mechanical strength of CS. Many related research on this area are still not fully unstated and occasionally they seem inconsistent in spite of the intent to be complementary. Therefore, a sensitive review may be needed to understand the role of graphene in CS/graphene carriers for future drug delivery applications.     

Metallic nanoparticles: technology overview & drug delivery applications in oncology

Importance of the field: The targeted delivery of therapeutic agents to tumour cells is a challenge because most of the chemotherapeutic agents distribute to the whole body, which results in general toxicity and poor acceptance by patients and sometimes discontinuation of the treatment. Metallic nanoparticles have been used for a huge number of applications in various areas of medical treatment. Metallic nanoparticles are emerging as new carrier and contrast agents in cancer treatment. These metallic nanoparticles have been used for imaging of tumour cells by means of active and passive targeting. Recent advances have opened the way to site-specific targeting and drug delivery by these nanoparticles.

Areas covered in this review: This review summarizes the mechanisms of passive and active targeted drug delivery by metallic nanoparticles and their potential use in cancer theranostics.

What the reader will gain: The reader will gain information on the development of tumour cells, advantages of modern methods of cancer treatment over the traditional method, targeted delivery of anticancer agents using nanoparticles, influence of nanotechnology on the quality and expectancy of life, and challenges, implications and future prospects of metallic nanoparticles as probes in cancer treatment.

Take home message: The development of metallic nanoparticles is rapid and multidirectional, and the improved practical potential of metallic nanoparticle highlights their potency as new tools for future cancer therapeutics modalities.     

皮肤真菌病新型局部给药系统研究进展

皮肤真菌病是易发病、易传染、易复发的疾病,严重影响患者生活质量。局部给药制剂直接作用于病变部位,使用方便,患者顺应性好,是皮肤真菌病临床治疗的首选。以脂质体、醇质体、微乳和脂质纳米粒等为代表的新型给药系统,可以提高药物的渗透性,减小药物透过,使其在皮肤局部蓄积,从而能够增强疗效、缩短疗程和减少不良反应,使皮肤真菌病的局部治疗更具有应用前景。本文综述了近年来国内外皮肤真菌病新型局部给药系统的研究进展。     

经内耳途径靶向脑给药的初步研究

本文探寻经内耳途径输送药物到脑部的可行性，为脑靶向给药提供一条崭新的研究思路。制备醋酸地塞米松(DA)固体脂质纳米粒(SLN)，建立相应的HPLC含量测定方法。经静脉和鼓室注射DA-SLN，并与地塞米松磷酸钠(DSP)溶液相比较，测定药物在脑脊液(CSF)和内耳外淋巴液(PL)中的浓度及药代动力学参数。结果表明，与静脉注射比较，鼓室注射药物在CSF的局部生物利用度显著提高，鼓室注射DA-SLN比静脉注射高2.5倍，鼓室注射DSP溶液比静脉注射高4.3倍。与DSP溶液比较，鼓室注射DA-SLN能明显增加进入CSF的药量和延长药物的作用时间，AUC和MRT分别较前者高13和19倍；并且药物在PL中分布减少，其AUC低76%。提示经内耳途径给药有望成为一种新的脑靶向方法，值得进一步研究。     

Lipid nanoparticles: Different preparation techniques,characterization, hurdles,and strategies for the production of solid lipid nanoparticles and nanostructured lipid carriers for oral drug delivery

The bioavailability of an orally administered drug primarily depends on its solubility in the GIT and its permeability across cell membranes. Also, a drug in solution form is preferred for conducting pharmacological, toxicological and pharmacokinetic studies during the drug development stage. Thus, poor water solubility not only limits a drug’s biological application but also challenges its pharmaceutical development. The use of lipid nanoparticles (LNs) in pharmaceutical technology has been reported for several years due to its important in green chemistry for several reasons specifically for its biochemical as “green” materials and biochemical processes as green processes that can be very environmentally friendly. Also, the physiological/physiologically related lipids (GRAS) made LNs usually enhance the drug absorption in the GIT. Hence, the pathways for absorption, metabolism, and transportation are present in the body, which may contribute to a large extent to the bio-fate of the lipidic carrier. Moreover, the LNs improves the mucosal adhesion and increases their GIT residence time. The LNs with a solid matrix are two types: solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLC). Also, their hydrophobic core provides a suitable environment for entrapment of hydrophobic drugs to improve its bioavailability. This review highlights and discusses the simple and easily scaled-up novel SLN and NLC along with their different production techniques, hurdles, and strategies for the production of LNs, characterization, lyophilization and drug release. Also, this review summarizes the research findings reported by the different researchers regarding the different method of preparation, excipients and their significant findings.     

Stimuli-responsive nanoscale drug delivery systems for cancer therapy

Abstract

Currently, with the rapid development of nanotechnology, novel drug delivery systems (DDSs) have made rapid progress, in which nanocarriers play an important role in the tumour treatment. In view of the conventional chemotherapeutic drugs with many restrictions such as nonspecific systemic toxicity, short half-life and low concentration in the tumour sites, stimuli-responsive DDSs can deliver anti-tumour drugs targeting to the specific sites of tumours. Owing to precise stimuli response, stimuli-responsive DDSs can control drug release, so as to improve the curative effects, reduce the damage of normal tissues and organs, and decrease the side effects of traditional anticancer drugs. At present, according to the physicochemical properties and structures of nanomaterials, they can be divided into three categories: (1) endogenous stimuli-responsive materials, including pH, enzyme and redox responsive materials; (2) exogenous stimuli-responsive materials, such as temperature, light, ultrasound and magnetic field responsive materials; (3) multi-stimuli responsive materials. This review mainly focuses on the researches and developments of these novel stimuli-responsive DDSs based on above-mentioned nanomaterials and their clinical applications.     

Block copolymer micelles as a solution for drug delivery problems

Micelles, nanosized colloidal particles with a hydrophobic core and hydrophilic shell, can be successfully used for the solubilisation of various poorly soluble pharmaceuticals, and demonstrate a series of attractive properties as drug carriers. Polymeric micelles, such as micelles formed by amphiphilic block copolymers, are of a special interest as they possess high stability both invitro and invivo, and good biocompatibility. Drug-loaded micelles can spontaneously accumulate in body areas with compromised vasculature (tumours, infarcts) via the enhanced permeability and retention (EPR) effect. Micelles made of stimuli-responsive (pH- or temperature-sensitive) amphiphilic block copolymers can release their contents in pathological areas demonstrating hyperthermia or acidosis. Various specific targeting ligand molecules, such as antibodies, can be attached to the micelle surface and bring drug-loaded micelles to, and into, target cells (cancer cells being a primary target). Micelles carrying various reporter (contrast) groups may become the imaging agents of choice in different imaging modalities. This review will consider some recent trends in using micelles as pharmaceutical carriers.     

Construction of nanoscale multicompartment liposomes for combinatory drug delivery

Liposomes are clinically used delivery systems for chemotherapeutic agents, biological macromolecules and diagnostics. Due to their flexibility in size and composition, different types of liposomes have been developed varying in surface and structural characteristics. Multicompartment liposomes constitute an attractive drug carrier system offering advantages in terms of inner vesicle protection, sustained drug release and possibility for combinatory (cocktail) therapies using a single delivery system. However, all previously described methodologies for multicompartment or multivesicular liposomes resulted in micrometer-sized vesicles limiting most pharmaceutical applications. In this work we report formulation of nanoscale multicompartment liposomes which maybe applicable for systemic administration. A small unilamellar vesicle (SUV) aqueous dispersion (DOPC:DOPG:CHOL) was used to hydrate a dried film of different lipid contents (DMPC:CHOL), followed by extrusion. The system was characterised by techniques such as photon correlation spectroscopy (PCS), zeta potential measurement, transmission electron microscopy (TEM) and laser scanning confocal microscopy (LSCM). We observed a single, multicompartment vesicle population composed of the two different bilayer types of approximately 200 nm in mean diameter rather than a mixture of two independent vesicle populations. In the case of tumour therapy, such multicompartment liposome systems can offer a single carrier for the delivery of two different modalities.     

Responsive polymer conjugates for drug delivery applications: recent advances in bioconjugation methodologies

Abstract

Protein–polymer conjugates have achieved tremendous attention in the last few years, since their importance in diverse fields including drug delivery, biotechnology and nanotechnology. Over the past few years, numerous chemical strategies have been developed to conjugate different synthetic polymers onto proteins and great progress has been made. Currently, there are a handful of therapeutic polymer conjugates that have been approved by the FDA, while many hundreds of products are under extensive clinical trials and preclinical development phases. In this way, the development of novel techniques for conjugation, especially living radical polymerisation (LRP) has greatly enhanced the potential to broaden the scope of therapeutic conjugates. As a consequence, versatile techniques have developed, such as the ‘grafting from’ approach, which allows modifications of biomacromolecules at the atomic level, and subsequently preparing well-defined stimuli-responsive conjugates. These strategies present a unique perspective for therapy expansion of a new generation of ‘smart’ products with proprieties that can be finely controlled and tuned rather than just enhanced. This article highlights recent advances in the synthesis and application of protein–polymer conjugates by controlled radical polymerisation techniques, with special emphasis on stimuli-responsive conjugates on new applications in biomedical and pharmaceutical areas.     

Decationized polyplexes for gene delivery

Gene therapy has received much attention in the field of drug delivery. Synthetic, nonviral gene delivery systems have gained increasing attention as vectors for gene therapy mainly due to a favorable immunogenicity profile and ease of manufacturing as compared to viral vectors. The great majority of these formulations are based on polycationic structures, due to their ability to interact with negatively charged nucleic acids to spontaneously form nanoparticles. In recent years, several polycationic systems have demonstrated high transfection in vitro. However, progress toward clinical applications has been slow, mainly because the cationic nature of these systems leads to intolerable toxicity levels, inappropriate biodistribution and unsatisfactory efficiency in vivo, particularly after systemic administration. Decationized polyplexes are a new class of gene delivery systems that have been developed as an alternative for conventional polycation-based systems. The major innovation introduced by decationized polyplexes is that these systems are based on neutral polymers, without any detrimental effect on the physicochemical stability or encapsulation ability, due to the transient presence of cationic charge and disulfide cross-links between the polymer chains by which the nucleic acids are physically entrapped in the particles. This editorial summarizes the most important features of decationized polyplexes and discusses potential implications for the development of new safe and efficient gene delivery systems.     

Gastroretentive microparticles for drug delivery applications

Many strategies have been proposed to explore the possibility of exploiting gastroretention for drug delivery. Such systems would be useful for local delivery, for drugs that are poorly soluble at higher pH or primarily absorbed from the proximal small intestine. Generally, the requirements of such strategies are that the vehicle maintains controlled drug release and exhibits prolonged residence time in the stomach. Despite widespread reporting of technologies, many have an inherent drawback of variability in transit times. Microparticulate systems, capable of distributing widely through the gastrointestinal tract, can potentially minimise this variation. While being retained in the stomach, the drug content is released slowly at a desired rate, resulting in reduced fluctuations in drug levels. This review summarises the promising role of microencapsulation in this field, exploring both floating and mucoadhesive microparticles and their application in the treatment of Helicobacter pylori, highlighting the clinical potential of eradication of this widespread infection.     

Microporation applications for enhancing drug delivery

Microporation involves the creation of micron-sized micropores or microchannels in the skin which can then allow the transport of water soluble molecules and macromolecules. Technologies which can create these microchannels in the skin include mechanical microneedles, thermal or radiofrequency ablation and laser ablation. These technologies will open a new frontier for the delivery of biopharmaceuticals, as these hydrophilic macromolecules cannot be delivered via the skin passively. Companies which are developing these technologies are discussed, along with potential hurdles to commercialization related to the elasticity of skin, immunogenicity issues, pore closure kinetics, or microneedle material and geometries. In spite of the obstacles, these technologies look very promising and are likely to revolutionize transdermal drug delivery in the near future. Bioavailability considerations and the potential use of inexpensive coated microneedles for mass immunizations are also discussed.     

叶酸受体介导的肿瘤靶向纳米递药系统

叶酸受体在上皮源性的恶性肿瘤细胞膜表面高度表达。叶酸靶向纳米递药系统具有叶酸-叶酸受体主动靶向和纳米递药系统被动靶向的双重优势,可实现化疗药物对肿瘤组织的靶向递送,有效提高药物疗效,减少毒副作用。本文就近年来研究较多的叶酸-脂质体、叶酸-树枝状聚合物、叶酸-聚合物胶束、叶酸-纳米球等叶酸受体介导的肿瘤靶向递药系统进行综述。     

Gastroretentive microparticles for drug delivery applications

Many strategies have been proposed to explore the possibility of exploiting gastroretention for drug delivery. Such systems would be useful for local delivery, for drugs that are poorly soluble at higher pH or primarily absorbed from the proximal small intestine. Generally, the requirements of such strategies are that the vehicle maintains controlled drug release and exhibits prolonged residence time in the stomach. Despite widespread reporting of technologies, many have an inherent drawback of variability in transit times. Microparticulate systems, capable of distributing widely through the gastrointestinal tract, can potentially minimise this variation. While being retained in the stomach, the drug content is released slowly at a desired rate, resulting in reduced fluctuations in drug levels. This review summarises the promising role of microencapsulation in this field, exploring both floating and mucoadhesive microparticles and their application in the treatment of Helicobacter pylori, highlighting the clinical potential of eradication of this widespread infection.