Docetaxel (DTX), one of the most effective chemotherapeutic agents for the treatment of metastatic breast cancer but finds limited clinical applications due to toxicity imparted by surfactant present in marketed formulation and non-specific bio-distribution of the drug. To address these issues, this study was undertaken by taking a novel approach of fabrication of DTX loaded scFv (Single chain variable fragment) conjugated human serum albumin (HSA) immunonanoparticles (INPs). Developed INPs were characterized for particle size, zeta potential, entrapment efficiency, in vitro drug release, stability, in vitro cell line studies and in vivo animal studies. DTX-HSA-INPs were spherical in shape with mean diameter of 160.7 +/- 5.5 nm and they showed specific binding to the targeted receptor when studied in vitro in cell line culture. It showed enhanced intracellular accumulation of INPs in EGFR expressing breast carcinoma cells as compared to EGFR negative breast carcinoma cells and nontargeted nanoparticles (NPs) Improved cytotoxic potential was demonstrated by DTX-HSA-INPs compared to marketed formulation in EGFR-expressing breast carcinoma cells (MDA-MB-468 and MDA-MB-231). Improved pharmacokinetic profile and long circulation in vivo in animals also revealed that the novel scFv targeted DTX-HSA-INPs can be a better and one of the promising alternatives for breast cancer therapy.
Abstract Background: Epirubicin-HCl is highly efficient for breast cancer management at a concentration of 60–90 mg/m2. However, its application is limited due to cumulative dose-dependent cardio-toxicity. Purpose: The main aim of this study was to formulate breast cancer-targeted liposomal carrier by surface conjugation of transferrin to minimize cardio-toxicity of drug along with improved pharmacokinetic profile. Method: Liposomes were formulated by ethanol injection method using HSPC, cholesterol and DSPG and later loaded with drug by the ammonium sulfate gradient method. The formulation was characterized for physicochemical properties like size, zeta potential, entrapment efficiency, TEM; in vitro tests like electro-flocculation, hemolysis and drug release; cell line study (MCF-7 cells); in vivo studies including LD50 determination, pharmacokinetic analysis, myocardial toxicity determination and stability. Results and discussion: Optimized formulation had molar ratio of 60:30:8:2 (HSPC:Chol:DSPG:mPEG-DSPE) with entrapment efficiency ∼83%, particle size below 200 nm and zeta potential about −20 mV. In vitro studies proved non-interfering property and drug release character of formulation while cell line studies demonstrated improvement in cell uptake and thereby increased cytotoxicity of targeted formulation. The IC50 value obtained for epirubicin solution, non-targeted and targeted liposomes was 0.675, 0.532 and 0.192 µg/ml, respectively. Furthermore, in vivo tests validated safety and distribution profile of prepared formulations. Conclusion: Apt properties of prepared Epirubicin-HCl liposomal formulation warrant its clinical application in breast cancer treatment after further studies.
Objective: The present investigation was aimed to develop and compare microemulsion and nanoemulsion for brain targeted intranasal delivery of tramadol to achieve maximum therapeutic efficacy in treatment of episodic and emergency pain.Methods: Tramadol microemulsion (TME) and tramadol nanoemulsion (TNE) were developed and evaluated for physical properties. Ex vivo diffusion and nasal toxicity of TME and TNE were assessed by using sheep nasal mucosa. Biodistribution, pharmacokinetic and pharmacodynamic studies in mice were also performed.Results: Globule sizes of TME and TNE were 16.69 +/- 3.21 and 136.3 +/- 4.3 nm, respectively. TNE was found be safe with respect to multiple dosing via nasal route. Both TME and TNE were stable during accelerated stability studies. AUC((0 -> 24)) in mice brain for TME and TNE was significantly higher as compared with tramadol solution. TME and TNE displayed significantly higher antinociceptive effect for a period of 16 h as compared with tramadol solution.Discussion: TME and TNE were delivered to brain, circumventing BBB in brisk manner, establishing immediately the minimum effective concentration required for therapeutic response. Significant enhancement in antinociceptive effect was observed after intranasal delivery of TME and TNE.Conclusion: Intranasal administration of TME and TNE would be effective in management of episodic and emergency pain treatment.
PURPOSE:The aim of present investigation was to effectively deliver ribonucleotide reductase subunit 1 (RRM1) targeted siRNA and assess chemo-sensitization of lung cancer cells against Gemcitabine hydrochloride. It was hypothesised that effective and selective delivery of RRM1 siRNA will help in the treatment of lung cancer chemotherapy using Gemcitabine hydrochloride by reducing drug dose and thereby, reduces dose related toxicity of Gemcitabine hydrochloride.METHODS:In this investigation, cRGD grafted siRNA nano-constructs were developed for efficient and targeted intracellular delivery of siRNA. Developed formulations were characterized for gel retardation assay, particle size, zeta potential, cryo transmission electron microscopy, serum stability, in vitro cytotoxicity, qualitative and quantitative cell uptake, gene expression, and chemo-sensitization.RESULTS:Complete complexation of siRNA with cRGD grafted nano-constructs was found at N/P ratio of 2.0. Naked siRNA was found to degrade within 6 h in presence of 50% serum while nano-constructs protected the complexed siRNA even after 24 h. RRM1 level significantly reduced when siRNA was delivered in nano-construct form as compared to naked siRNA. Pre-exposure of RRM1 siRNA decreased the IC50 value of Gemcitabine hydrochloride 5 folds in A-549 cells compared to Gemcitabine hydrochloride alone.CONCLUSION:These results suggest the application of present siRNA delivery strategy to potentiate the chemotherapeutic effect by means of chemosensitization which may be utilized for effective and thorough remission of lung cancer.
Inhalation delivery of voriconazole loaded large porous particles represent an effective and safe way to prolong pulmonary residence of voriconazole.
Abstract This study was aimed to develop poly(dl-lactide-co-glycolide) (PLGA) nanoparticle of highly water soluble antibiotic drug, netilmicin sulfate (NS) with improved entrapment efficiency (EE) and antibacterial activity. Dextran sulfate was introduced as helper polymer to form electrostatic complex with NS. Nanoparticles were prepared by double emulsification method and optimized using 25-1 fractional factorial design. EE was mainly influenced by dextran sulfate: NS charge ratio and PLGA concentration, whereas particle size (PS) was affected by all factors examined. The optimized NS-loaded-NPs had EE and PS of 93.23 ± 2.7% and 140.83 ± 2.4 nm respectively. NS-loaded-NPs effectively inhibited bacterial growth compared to free NS. Sustained release protected its inactivation and reduced the decline in its killing activity over time even in presence of bronchial cells. A MIC value of 18 μg/mL was observed for NPs on P. aeruginosa. Therefore, NPs with sustained bactericidal efficiency against P. aeruginosa may provide therapeutic benefit in chronic pulmonary infection, like cystic fibrosis.
Cationic liposomes have long been used as non-viral vectors for small interfering RNA (siRNA) delivery but are associated with high toxicity, less transfection efficiency, and in vivo instability. In this investigation, we have developed siRNA targeted to RRM1 that is responsible for development of resistance to gemcitabine in cancer cells. Effect of different lipid compositions has been evaluated on formation of stable and less toxic lipoplexes. Optimized cationic lipoplex (D2CH) system was comprised of dioleoyl-trimethylammoniumpropane (DOTAP), dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), hydrogenated soya phosphocholine (HSPC), cholesterol, and methoxy(polyethyleneglycol)2000–1,2-distearoyl-sn-glycero-3-phosphoethanolamine (mPEG2000–DSPE). D2CH lipoplexes have shown particle size (147.5 ± 2.89 nm) and zeta potential (12.26 ± 0.54 mV) characteristics essential for their in vivo use. In vitro cytotoxicity study has shown low toxicity of developed lipoplexes as compared with lipofectamine-2000 up to N/P ratio as high as 7.5. Cell uptake studies and gene expression studies have confirmed intracellular availability of siRNA. In addition, developed lipoplexes also showed ~3 times less hemolytic potential as compared with DOTAP/DOPE lipoplexes at lipid concentration of 5 mg/mL. Lipoplexes also maintained particle size less than 200 nm on exposure to high electrolyte concentration and showed >70% siRNA retention in presence of serum showing siRNA protection conferred by lipoplexes. Furthermore, in vivo acute toxicity studies in mice showed that formulation was non-toxic up to a dosage of 0.75 mg of siRNA/kg as lipoplexes and 300 mg lipid/kg as blank liposomes indicating tolerability of lipoplexes at a dose much higher than required for therapeutic use. Promising results of this study warrant further investigation of developed siRNA lipoplexes for cancer treatment.
This study was aimed to develop and evaluate p53 polyplex-loaded enteric-coated calcium pectinate microbeads for oral gene delivery as an effective novel alternative for colorectal cancer therapy. Mutation in p53 is the key event in colorectal cancer (CRC) and an important target for the treatment of CRC through gene therapy. Polymethacrylates-based non-viral vectors were evaluated for their ability to complex, protect and transfect p53 (wt) into colon cancer cell line. Polyplexes were formulated by complexation of cationic polymer with anionic pDNA at different N/P ratios. p53 polyplex-loaded calcium pectinate (CP) microbeads were prepared by ionotropic gelation of pectin with calcium chloride and coated with Eudragit® S100. In vitro release studies showed that enteric-coated CP microbeads protected the release of p53 polyplex in upper GIT with less than 10% release. In-vitro cell line studies and in vivo studies in rat showed that polymethacrylate carrier could transfect the pDNA effectively. Results of in vivo gene expression study further confirmed the ability of enteric-coated calcium pectinate microbeads to deliver pDNA specifically to rat colon. Conclusively, enteric-coated calcium pectinate microbeads released p53 polyplex specifically in colon and could serve as an effective alternative for CRC therapy.
Development of effective vector for intracellular delivery of siRNA has always been a challenge due to its hydrophilicity, net negative surface charge and sensitivity against nucleases in biological milieu. The present investigation was aimed to develop a novel non-viral liposomal carrier for siRNA delivery. Nano-precipitate of calcium phosphate was entrapped in liposomes composed of a neutral lipid (DPPC), a fusogenic lipid (DOPE), a PEGylated lipid (DSPE-mPEG2000) and cholesterol. siRNA was made permeable through liposomal bilayer and complexed to calcium phosphate precipitates inside the liposomes. siRNA entrapped liposomes were further grafted with cRGD to achieve targeting potential against cancer cells. More than 80% of siRNA was entrapped inside the liposomes having average particle size below 150 nm. Cryo-transmission electron microscopy revealed the intra-liposomal calcium phosphate precipitation and unilamellar morphology of prepared liposomes. The viability of A549 lung cancer cells was significantly higher after treatment with siRNA entrapped liposomes as compared to Lipofectamine2000 complexed siRNA. Fluorescent intensity in lung carcinoma cells was significantly higher after exposure to fluorescent siRNA entrapped liposomes than with Lipofectamine2000, which were confirmed by both confocal microscopy and flow cytometry. Live imaging by confocal microscopy ascertained the targeting efficacy of cRGD grafted liposomes compared to naked siRNA and non-grafted liposomes. Developed liposomal formulation showed effective protection of siRNA against serum nucleases along with less haemolytic potential and excellent stability against electrolyte induced flocculation. At 5 nM concentration gene expression of target protein was reduced up to 24.1 ± 3.4% while Lipofectamine2000 reduced expression level up to 26.35 ± 1.55%. In vivo toxicity in mice suggested admirable safety profile for developed lipid based delivery vector. These results advocate that prepared liposomal system would be of high value for intracellular delivery of siRNA.
Polyethylene glycol (PEG) conjugation is a rapidly evolving strategy to solve hurdles in therapeutic delivery and is being used as an add-on tool to the traditional drug delivery methods. Chemically, PEGylation is a term used to denote modification of therapeutic molecules by conjugation with PEG. Efforts are constantly being made to develop novel strategies for conjugation of PEG with these molecules in order to increase its current applications. These strategies are specific to the therapeutic system used and also depend on the availability of activated PEGylating agents. Therefore, a prior knowledge is essential in selecting appropriate method for PEGylation. Once achieved, a successful PEGylation can amend the pharmacokinetic and pharmacodynamic outcomes of therapeutics. Specifically, the primary interest is in their ability to decrease uptake by reticuloendothelial system, prolong blood residence, decrease degradation by metabolic enzymes and reduce protein immunogenicity. The extensive research in this field has resulted into many clinical studies. The knowledge of outcome of these studies gave a good feedback and lessons which helped researchers to redesign PEG conjugates with improved features which can increase the chance of hitting the market. In light of this, the current paper highlights the approaches, novel strategies and the utilization of modern concept for PEG conjugation with respect to various bioactive components of clinical relevance. Moreover, this review also discusses potential clinical outcomes of the PEG conjugation, regulatory approved PEGylated product, clinical trials for newer formulations, and also provides future prospects of this technology.
Receptor-targeted drug delivery has been extensively explored for active targeting. However, the scarce clinical applications of such delivery systems highlight the implicit hurdles in development of such systems. These hurdles begin with lack of knowledge of differential expression of receptors, their accessibility and identification of newer receptors. Similarly, ligand-specific challenges range from proper choice of ligand and conjugation chemistry, to release of drug/delivery system from ligand. Finally, nanocarrier systems, which offer improved loading, biocompatibility and reduced premature degradation, also face multiple challenges. This review focuses on understanding these challenges, and means to overcome such challenges to develop efficient, targeted drug-delivery systems.
The epidermal growth factor receptor (EGFR) is a cell-surface receptor belonging to ErbB family of tyrosine kinase and it plays a vital role in the regulation of cell proliferation, survival and differentiation. However; EGFR is aberrantly activated by various mechanisms like receptor overexpression, mutation, ligand-dependent receptor dimerization, ligand-independent activation and is associated with development of variety of tumors. Therefore, specific EGFR inhibition is one of the key targets for cancer therapy. Two major approaches have been developed and demonstrated benefits in clinical trials for targeting EGFR; monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs). EGFR inhibitors like, cetuximab, panitumumab, etc. (mAbs) and gefitinib, erlotinib, lapatinib, etc. (TKIs) are now commercially available for treatment of variety of cancers. Recently, many other agents like peptides, nanobodies, affibodies and antisense oligonucleotide have also shown better efficacy in targeting and inhibiting EGFR. Now a days, efforts are being focused to identify molecular markers that can predict patients more likely to respond to anti-EGFR therapy; to find out combinatorial approaches with EGFR inhibitors and to bring new therapeutic agents with clinical efficacy. In this review we have outlined the role of EGFR in cancer, different types of EGFR inhibitors, preclinical and clinical status of EGFR inhibitors as well as summarized the recent efforts made in the field of molecular EGFR targeting.
Introduction: Over the past decades, proteins have emerged as versatile carriers for the diagnosis and treatment of cancer, diabetes, rheumatoid arthritis, and many more diseases. Proteins have gained considerable attention in formulation of several delivery systems for anticancer drugs due to their nontoxic, non-immunogenic, biocompatible and biodegradable nature. Proteins are good candidates for conjugation with drugs as they provide good pharmacokinetics as well as better cancer tissue accumulation. Protein nanoparticulate systems are also of advancing importance owing to their modifiable functionalities and potential applications in various biological fields. The customizable nature of proteins also makes them outstanding carriers as target-specific delivery systems. Areas covered: This review emphasizes on protein conjugates (drug-albumin, drug-gelatin, drug-transferrin, and drug-antibody conjugates), protein nanoparticles (prepared using albumin, gelatin, casein, silk proteins, elastin, and lectins), surface modification of protein nanoparticles (using surfactant, polyethylene glycol, cationic/thermosensitive polymers, folic acid, monoclonal antibodies, and peptides/proteins), and their preclinical and clinical status with respect to cancer therapy. Expert opinion: The major obstacles for commercial success of protein-based delivery are lack of inexpensive as well as quality methods for their preparation and quality control; and if overcome, proteins will stand out as a superior drug-delivery carrier for cancer therapy.
Introduction: Over the past decades, proteins have emerged as versatile carriers for the diagnosis and treatment of cancer, diabetes, rheumatoid arthritis, and many more diseases. Proteins have gained considerable attention in formulation of several delivery systems for anticancer drugs due to their nontoxic, non-immunogenic, biocompatible and biodegradable nature. Proteins are good candidates for conjugation with drugs as they provide good pharmacokinetics as well as better cancer tissue accumulation. Protein nanoparticulate systems are also of advancing importance owing to their modifiable functionalities and potential applications in various biological fields. The customizable nature of proteins also makes them outstanding carriers as target-specific delivery systems. Areas covered: This review emphasizes on protein conjugates (drug-albumin, drug-gelatin, drug-transferrin, and drug-antibody conjugates), protein nanoparticles (prepared using albumin, gelatin, casein, silk proteins, elastin, and lectins), surface modification of protein nanoparticles (using surfactant, polyethylene glycol, cationic/thermosensitive polymers, folic acid, monoclonal antibodies, and peptides/proteins), and their preclinical and clinical status with respect to cancer therapy. Expert opinion: The major obstacles for commercial success of protein-based delivery are lack of inexpensive as well as quality methods for their preparation and quality control; and if overcome, proteins will stand out as a superior drug-delivery carrier for cancer therapy.
Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vascular system, which may lead to right-heart failure or early death in the absence of effective treatment. The current therapy for PAH mainly includes phosphodiesterase inhibitors, prostanoids and endothelin receptor antagonists. These, however, have adverse effects when administered via conventional routes. There is a clear and critical need for the development of a novel delivery system that can efficiently deliver the drug to lung vasculature and minimize adverse effects. This article summarizes the inhalation devices and recent patents in the area of inhalable therapy for the treatment of PAH. Various patents are discussed that describe the application of inhalable therapy to target lung vasculature and to reduce dose-related side effects in PAH treatment. Entry of some inhalable delivery approaches into clinical trials is the result of progress in inhalable therapies for the treatment of PAH.
RNA interference (RNAi) is a wondrous phenomenon that silences the expression of targeted genes via distinct messenger RNA degradation pathways. It has the potential as a therapeutic agent for variety of diseases, including viral infections, cancer, and immune diseases. RNAi mainly conducts gene regulation by 3 ways: microRNA, short hairpin RNA, and small interfering RNA. However, in vivo delivery of RNAi therapeutics is restricted because of charge density, molecular weight, and instability in the presence of nucleases. Furthermore, intracellular accumulation and endosomal escape have remained significant barriers in the delivery of these macromolecules. Many viral and nonviral delivery vectors have been thoroughly investigated to overcome these barriers. Researchers have found applications for RNAi in a variety of diseases and, hence, various delivery systems have been explored to satisfy the need. Both local and systemic strategies have been utilized to elicit RNAi's effect and each carries its own therapeutic implications with varying margins of safety. This review is an effort to describe the types of RNAi and their application in a variety of diseases using both local and systemic delivery approaches. It is sure that advancement in this direction will evolve a new landscape for treating a range of diseases.