Advanced drug delivery systems: Nanotechnology of health design A review

Herbonanoceuticals: A Novel Beginning in Drug Discovery and Therapeutics

The Indian pharmaceutical industry is the world’s second largest industry (by volume) that develops products and market drugs licensed for use as medications. Medicines manufactured in the modern era are associated with major controversies such as non–target specificity, resistance, repeated administration, immune rejection, and other adverse effects on the body. Thus, there is a great need to find drugs that do not raise the aforementioned issues. Nature is an excellent hub providing a diverse range of phytoconstituents that open the way to phototherapeutics, which need a scientific path to deliver the active elements in a supported way to increase patient compliance and reduce the need for repeated administration. To discover a novel phytochemical as a lead compound for a therapeutic purpose is a real challenge. In former times, drug discovery was a complex process, as it took several years to find a lead compound for use against a particular disease. Nowadays, however, virtual screening methods have been developed, which are target specific, time consuming, and cost effective. To avoid increased and repeated administration of a drug, nanosized drug delivery systems for herbal drugs have been developed to enhance the activity and overcome problems associated with synthetic medicines. This review summarizes three main fields: drug discovery, docking for drug design, and last—but not least—drug delivery systems. Nowadays, nanobased drug delivery systems are in demand for delivery of herbal medicines used for therapeutic purposes. Herbonanoceuticals—herbal drugs of a nanosize—have better remedial value and fewer detrimental effects than modern medicines. Therefore, herbonanoceuticals can be a boon in the field of therapeutics.

Current Challenges and Opportunities in Treating Glioblastoma

Glioblastoma multiforme (GBM), the most common and aggressive primary brain tumor, has a high mortality rate despite extensive efforts to develop new treatments. GBM exhibits both intra- and intertumor heterogeneity, lending to resistance and eventual tumor recurrence. Large-scale genomic and proteomic analysis of GBM tumors has uncovered potential drug targets. Effective and “druggable” targets must be validated to embark on a robust medicinal chemistry campaign culminating in the discovery of clinical candidates. Here, we review recent developments in GBM drug discovery and delivery. To identify GBM drug targets, we performed extensive bioinformatics analysis using data from The Cancer Genome Atlas project. We discovered 20 genes, BOC, CLEC4GP1, ELOVL6, EREG, ESR2, FDCSP, FURIN, FUT8-AS1, GZMB, IRX3, LITAF, NDEL1, NKX3-1, PODNL1, PTPRN, QSOX1, SEMA4F, TH, VEGFC, and C20orf166AS1 that are overexpressed in a subpopulation of GBM patients and correlate with poor survival outcomes. Importantly, nine of these genes exhibit higher expression in GBM versus low-grade glioma and may be involved in disease progression. In this review, we discuss these proteins in the context of GBM disease progression. We also conducted computational multi-parameter optimization to assess the blood-brain barrier (BBB) permeability of small molecules in clinical trials for GBM treatment. Drug delivery in the context of GBM is particularly challenging because the BBB hinders small molecule transport. Therefore, we discuss novel drug delivery methods, including nanoparticles and prodrugs. Given the aggressive nature of GBM and the complexity of targeting the central nervous system, effective treatment options are a major unmet medical need. Identification and validation of biomarkers and drug targets associated with GBM disease progression present an exciting opportunity to improve treatment of this devastating disease.

Advanced smart biomaterials and constructs for hard tissue engineering and regeneration

Hard tissue repair and regeneration cost hundreds of billions of dollars annually worldwide, and the need has substantially increased as the population has aged. Hard tissues include bone and tooth structures that contain calcium phosphate minerals. Smart biomaterial-based tissue engineering and regenerative medicine methods have the exciting potential to meet this urgent need. Smart biomaterials and constructs refer to biomaterials and constructs that possess instructive/inductive or triggering/stimulating effects on cells and tissues by engineering the material's responsiveness to internal or external stimuli or have intelligently tailored properties and functions that can promote tissue repair and regeneration. The smart material-based approaches include smart scaffolds and stem cell constructs for bone tissue engineering; smart drug delivery systems to enhance bone regeneration; smart dental resins that respond to pH to protect tooth structures; smart pH-sensitive dental materials to selectively inhibit acid-producing bacteria; smart polymers to modulate biofilm species away from a pathogenic composition and shift towards a healthy composition; and smart materials to suppress biofilms and avoid drug resistance. These smart biomaterials can not only deliver and guide stem cells to improve tissue regeneration and deliver drugs and bioactive agents with spatially and temporarily controlled releases but can also modulate/suppress biofilms and combat infections in wound sites. The new generation of smart biomaterials provides exciting potential and is a promising opportunity to substantially enhance hard tissue engineering and regenerative medicine efficacy.

Dendrimeric Poly(Epsilon-Lysine) Delivery Systems for the Enhanced Permeability of Flurbiprofen across the Blood-Brain Barrier in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive brain disorder and age-related disease characterised by abnormal accumulation of β-amyloid (Aβ). The development of drugs to combat AD is hampered by the lack of therapeutically-active molecules able to cross the blood-brain barrier (BBB). It is agreed that specifically-designed carriers, such as dendrimers, could support the drug penetration across the BBB. The aim of this study was to design biocompatible and biodegradable dendrimeric delivery systems able to carry Flurbiprofen (FP), as drug for AD treatment, across the BBB and liberate it at the target tissue. These dendrons were synthesised using solid-phase peptide synthesis method and characterised by mass spectrometry and fourier-transform infrared spectroscopy (FTIR). The results revealed successful synthesis of dendrons having FP been integrated during the synthesis at their branching ends. Cytotoxicity assays demonstrated the biocompatibility of the delivery systems, whereas HPLC analysis showed high percentages of permeability across an in vitro BBB model for FP-integrated dendrons. Results also revealed the efficiency of drug conjugates on the γ-secretase enzyme in target cells with evidence of eventual drug release by hydrolysis of the carrier. This study demonstrates that the coupling of FP to dendrimeric delivery systems can successfully be achieved during the synthesis of the poly(epsilon-lysine) macromolecules to improve the transport of the active drug across the BBB.

Resurrection of Nalidixic Acid: Evaluation of Water-Based Nanoformulations as Potential Nanomedicine

Resistance to quinolone antibiotics has been a serious problem ever since nalidixic acid was introduced into clinical medicine. Over time, resistance of pathogenic microbes to nalidixic acid led to the design of novel variants to revive its potential application. In the present work, a series of eight nanoformulations of nalidixic acid-based diacyl and sulfonyl acyl hydrazine derivatives were prepared. All nanoformulations were found to be stable at different storage temperatures. Antibacterial and anticandida activity of the eight nanoformulations presented encouraging results when compared with their non-nano parent counterparts. The nanoformulations of chloro, furanyl, and sulfonyl acyl substituted derivatives of nalidixic acid displayed most promising results (MIC ranging from 50 to 100 μg mL-1) against the tested bacteria and yeast. Among the screened bacteria, Acinetobacter baumannii displayed maximum sensitivity to the above nanoformulations. Biosafety study on the mammalian model-wax moth, Galleria mellonella-showed that all eight prepared nanoformulations were absolutely nontoxic to the larvae and subsequent pupae and hence may likely have no or low toxicity against mammalian systems.

Enhancing the Delivery of Chemotherapeutics: Role of Biodegradable Polymeric Nanoparticles

While pharmaceutical drugs have revolutionized human life, there are several features that limit their full potential. This review draws attention to some of the obstacles currently facing the use of chemotherapeutic drugs including low solubility, poor bioavailability and high drug dose. Overcoming these issues will further enhance the applicability and potential of current drugs. An emerging technology that is geared towards improving overall therapeutic efficiency resides in drug delivery systems including the use of polymeric nanoparticles which have found widespread use in cancer therapeutics. These polymeric nanoparticles can provide targeted drug delivery, increase the circulation time in the body, reduce the therapeutic indices with minimal side-effects, and accumulate in cells without activating the mononuclear phagocyte system (MPS). Given the inroads made in the field of nanodelivery systems for pharmaceutical applications, it is of interest to review and emphasize the importance of Polymeric nanocarrier system for drug delivery in chemotherapy.

Nanobiotechnology medical applications: Overcoming challenges through innovation

Biomedical Nanotechnology (BNT) has rapidly become a revolutionary force that is driving innovation in the medical field. BNT is a subclass of nanotechnology (NT), and often operates in cohort with other subclasses, such as mechanical or electrical NT for the development of diagnostic assays, therapeutic implants, nano-scale imaging systems, and medical machinery. BNT is generating solutions to many conventional challenges through the development of enhanced therapeutic delivery systems, diagnostic techniques, and theranostic therapies. Therapeutically, BNT has generated many novel nanocarriers (NCs) that each express specifically designed physiochemical properties that optimize their desired pharmacokinetic profile. NCs are also being integrated into nanoscale platforms that further enhance their delivery by controlling and prolonging their release profile. Nano-platforms are also proving to be highly efficient in tissue regeneration when combined with the appropriate growth factors. Regarding diagnostics, NCs are being designed to perform targeted delivery of luminescent tags and contrast agents that enhance the NC -aided imaging capabilities and resulting diagnostic accuracy of the presence of diseased cells. This technology has also been advancing the ability for surgeons to practice true precision surgical techniques. Incorporating therapeutic and diagnostic NC-components within a single NC can facilitate both functions, referred to as theranostics, which facilitates real-time in vivo tracking and observation of drug release events via enhanced imaging. Additionally, stimuli-responsive theranostic NCs are quickly developing as vectors for tumor ablation therapies by providing a model that facilitates the location of cancer cells for the application of an external stimulus. Overall, BNT is an interdisciplinary approach towards health care, and has the potential to significantly improve the quality of life for humanity by significantly decreasing the treatment burden for patients, and by providing non-invasive therapeutics that confer enhanced therapeutic efficiency and safety

Pharmaceutical Applications of Cellulose Ethers and Cellulose Ether Esters

Cellulose ethers have proven to be highly useful natural-based polymers, finding application in areas including food, personal care products, oil field chemicals, construction, paper, adhesives, and textiles. They have particular value in pharmaceutical applications due to characteristics including high glass transition temperatures, high chemical and photochemical stability, solubility, limited crystallinity, hydrogen bonding capability, and low toxicity. With regard to toxicity, cellulose ethers have essentially no ability to permeate through gastrointestinal enterocytes and many are already in formulations approved by the U.S. Food and Drug Administration. We review pharmaceutical applications of these valuable polymers from a structure-property-function perspective, discussing each important commercial cellulose ether class; carboxymethyl cellulose, methyl cellulose, hydroxypropylcellulose, hydroxypropyl methyl cellulose, and ethyl cellulose, and cellulose ether esters including hydroxypropyl methyl cellulose acetate succinate and carboxymethyl cellulose acetate butyrate. We also summarize their syntheses, basic material properties, and key pharmaceutical applications.

An emerging integration between ionic liquids and nanotechnology: general uses and future prospects in drug delivery

There is a growing need to develop drug-delivery systems that overcome drawbacks such as poor drug solubility/loading/release, systemic side effects and limited stability. Ionic liquids (ILs) offer many advantages and their tailoring represents a valuable tuning tool. Nano-based systems are also prized materials that prevent drug degradation, enhance their transport/distribution and extend their release. Consequently, structures containing ILs and nanoparticles (NPs) have been developed to attain synergistic effects. This overview on the properties of ILs, NPs and of their combined structures, reveals the recent advances in these areas through a review of pertinent literature. The IL-NP structures present enhanced properties and the subsequent performance upgrade proves to be useful in drug delivery, although much is yet to be done.

Nanotechnology and Glycosaminoglycans: Paving the Way Forward for Ovarian Cancer Intervention

Ovarian cancer (OC) has gained a great deal of attention due to its aggressive proliferative capabilities, high death rates and poor treatment outcomes, rendering the disease the ultimate lethal gynaecological cancer. Nanotechnology provides a promising avenue to combat this malignancy by the niche fabrication of optimally-structured nanomedicines that ensure potent delivery of chemotherapeutics to OC, employing nanocarriers to act as "intelligent" drug delivery vehicles, functionalized with active targeting approaches for precision delivery of chemotherapeutics to overexpressed biomarkers on cancer cells. Recently, much focus has been implemented to optimize these active targeting mechanisms for treatment/diagnostic purposes employing nanocarriers. This two-part article aims to review the latest advances in active target-based OC interventions, where the impact of the newest antibody, aptamer and folate functionalization on OC detection and treatment is discussed in contrast to the limitations of this targeting mechanism. Furthermore, we discuss the latest advances in nanocarrier based drug delivery in OC, highlighting their commercial/clinical viability of these systems beyond the realms of research. Lastly, in the second section of this review, we comprehensively discussed a focus shift in OC targeting from the well-studied OC cells to the vastly neglected extracellular matrix and motivate the potential for glycosaminoglycans (GAGs) as a more focused extracellular molecular target.

Biosynthesis, characterization and leishmanicidal activity of a biocomposite containing AgNPs-PVP-glucantime

AIM

Development of functionalized nanocomposites containing AgNPs-PVP-Glucantime^® to evaluate their leishmanicidal activity as a novel method for improving the pharmacological properties of the drug Glucantime^® against extracellular promastigotes and intracellular amastigotes of Leishmania amazonensis in vitro to treat cutaneous leishmaniasis.

MATERIALS & METHODS

The silver nanoparticles and nanocomposites prepared containing silver nanoparticles, polyvinylpyrrolidone and different amounts of Glucantime were characterized using transmission electron microscopy, x-ray diffraction, energy-dispersive x-ray spectroscopy and ζ potential analysis; in addition, the in vitro cytotoxicity was evaluated.

RESULTS

The nanocomposites showed an inhibitory effect on the cellular viability of promastigote forms, with values of 47.06, 51.71 and 65.67% for nanocomposite₁, nanocomposite₂ and nanocomposite₃, respectively, as well as a dose-dependent decrease in the infectivity index, with values of 33.33 and 23% for nanocomposite₂ and nanocomposite₃, respectively.

CONCLUSION

The proposed nanocomposite reveals leishmanial activity and the absence of cytotoxicity in macrophages. Further investigations will be conducted in vivo.

Bridging the Knowledge of Different Worlds to Understand the Big Picture of Cancer Nanomedicines

Explosive growth of nanomedicines continues to significantly impact the therapeutic strategies for effective cancer treatment. Despite the significant progress in the development of advanced nanomedicines, successful clinical translation remains challenging. As cancer nanomedicine is a multidisciplinary field, the fundamental problem is that the knowledge gaps stem from different vantage points in the understanding of cancer nanomedicines. The complexities and heterogenecity of both nanomedicines and cancer are further demanding the integration of highly diverse expertise to develop clinically translatable cancer nanomedicines. This progress report aims to discuss the current understanding of cancer nanomedicines between different research areas in terms of nanoparticle engineering, formulation, tumor patho-physiology and clinical medicine, as well as to identify the knowledge gaps lying at the interface between the different fields of research in nanomedicine. Here we also highlight for the necessity to harmonize the multidisciplinary effort in the research of nanomedicines in order to bridge the knowledge and to advance the full understanding in cancer nanomedicines. A paradigm shift is needed in the strategic development of disease specific nanomedicines in order to foster the successful translation into clinic of future cancer nanomedicines.

Multianalytical approach for surface- and tip-enhanced infrared spectroscopy study of a molecule–metal conjugate: deducing its adsorption geometry

Multianalytical approach to the surface-enhanced infrared absorption spectroscopy (SEIRA) and tip-enhanced infrared nanospectroscopy (TEIRA) studies of α-methyl-dl-tryptophan adsorption geometry on a gold nanoparticle surface.

Remote magnetic switch off microgate for nanofluidic drug delivery implants

In numerous pathologies, implantable drug delivery devices provide advantages over conventional oral or parenteral approaches. Based on the site of implantation and release characteristics, implants can afford either systemic delivery or local administration, whereby the drug is delivered at or near the site of intended action. Unfortunately, current implantable drug delivery systems provide limited options for intervention in the case of an adverse reaction to the drug or the need for dosage adjustment. In the event that drug delivery must be terminated, an urgent surgical retrieval may be the only reliable option. This could be a time sensitive and costly effort, requiring access to trained professionals and emergency medical facilities. To address such limitations, here we demonstrate, in vitro and ex vivo, a novel microsystem for the rapid and effective switch off of drug delivery from an implantable nanofluidic system, by applying a safe external electromagnetic field in the FDA approved dose range. This study represents a proof of concept for a technology with potential for broad applicability to reservoir-based delivery implants for both complete interruption or remote titration of drug administration.

Modulation of fibronectin and laminin expression by Rhodium (II) citrate-coated maghemite nanoparticles in mice bearing breast tumor

Degradation of cellular matrix is one of the important processes related to the progression of breast cancer. Tumor cells have the ability to exhibit necessary conditions for growth and survival, promoting degradation processes of extracellular matrix proteins, such as laminin (LN) and fibronectin (FN). In this study, we evaluated whether treatments, based on free rhodium (II) citrate (Rh₂(H₂cit)₄), maghemite nanoparticles coated with citrate (Magh-cit) and maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh₂(H₂cit)₄), in murine metastatic breast carcinoma models can modulate the expression of laminin and fibronectin proteins. Synthesized nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and dynamic light scattering. The expression of FN and LN was assessed using immunohistochemistry and western blotting. The gene expression of FN1 and LAMA1 were evaluated using real-time PCR. The FN1 and LAMA1 transcripts from the Magh-Rh₂(H₂cit)₄ treated group were 95% and 94%, respectively, lower than the control group. Significant reduction in tumor volume for animals treated with Magh-Rh₂(H₂cit)₄ was observed, of about 83%. We witnessed statistically significant reductions of FN and LN expression following treatment with Magh-Rh₂(H₂cit)₄. We have demonstrated that the antitumor effects of Magh-Rh₂(H₂cit)₄ and Rh₂(H₂cit)₄ regulate the expression of FN and LN in metastatic breast tumors.

In vitro and in vivo delivery of artemisinin loaded PCL-PEG-PCL micelles and its pharmacokinetic study

Artemisinin (ART) is a natural anti-malarial sesquiterpene lactone with anticancer properties, but its application is limited because of its low water solubility. To increase the bioavailability and water solubility of ART, we synthesized three series of poly (ɛ-caprolactone)-poly (ethylene glycol)-poly (ɛ-caprolactone) (PCL-PEG-PCL) tri-block copolymers. The structure of the copolymers was characterized by HNMR, FTIR, DSC and GPC techniques. ART was encapsulated inside micelles by a nanoprecipitation method which leading to the formation of ART/PCL-PEG-PCL micelles. The obtained micelles were characterized by DLS and AFM technique. The results showed that the average size of micelles was about 83.22 nm. ART was encapsulated into PCL-PEG-PCL micelles with encapsulation efficacy of 89.23 ± 1.41%. In vivo results demonstrated that this formulation significantly increased drug accumulation in tumours. Pharmacokinetic study in rats revealed that in vivo drug exposure of ART was significantly increased and prolonged by intravenously administering ART-loaded micelles when compared with the same dose of free ART. The MTT assay showed that bare PCL-PEG-PCL micelles is non-toxic to MCF7 and 4T1 cancer cell lines whereas the ART/PCL-PEG-PCL micelles showed a specific toxicity to both cancer cell lines. Therefore, the polymeric micellar formulation of ART based copolymer could provide a desirable process for ART delivery.

Hydrophilically modified self-assembling α-tocopherol derivative as niosomal nanocarrier for improving clarithromycin oral bioavailability

Synthesis of biocompatible and cost-effective novel nonionic surfactants from renewable resources has been the subject of greater scientific interest for enhancing the bioavailability of less water-soluble drugs. The present study focuses on the synthesis of α-tocopherol-based novel biocompatible nonionic surfactant and its evaluation for forming clarithromycin-loaded niosomal drug delivery system. α-tocopherol was hydrophilically modified through multistep reactions and characterized using mass and ¹H NMR spectroscopic techniques. Drug-loaded niosomal vesicles were investigated for entrapment efficiency (%EE), size, polydispersity index (PDI), zeta potential (ζ) and morphology using LC-MS, dynamic light scattering (DLS) and atomic force microscopy (AFM). Blood haemolysis, cell culture and acute toxicity tests were performed to investigate its biocompatibility. In vivo oral bioavailability of clarithromycin loaded in niosomal formulation was studied in rabbits. The vesicles were spherical in shape and entrapped up to 75 ± 2.57% of the drug. They exhibited a homogeneous size distribution with a mean diameter of 245 ± 4.66 nm. The surfactant was quite haemocompatible, low cytotoxic and safe in mice. Improved oral bioavailability of clarithromycin was achieved when carried in α-tocopherol-based niosomes. Results obtained showed that the synthesized amphiphile is biocompatible and has excellent capability for formation of niosomal vesicles and enhancing oral bioavailability of less water-soluble drugs like clarithromycin.

Capsaicin-loaded folic acid-conjugated lipid nanoparticles for enhanced therapeutic efficacy in ovarian cancers

In this study, folic acid-conjugated lipid nanoparticles were successfully prepared to enhance the active targeting of capsaicin (CAP) in ovarian cancers. The particles were nanosized and exhibited a controlled release of drug in the physiological conditions. The folic acid (FA)-conjugated system exhibited a remarkably higher uptake of nanoparticles in the cancer cells compared to that of non-targeted system. The folate-conjugated CAP-loaded lipid nanoparticles (CFLN) upon interacting with cancer cells were internalized via receptor-mediated endocytosis mechanism and resulted in higher concentration in the cancer cells. Consistently, CFLN showed a remarkably higher toxic effect compared to that of non-targeted nanoparticle system. CFLN showed significantly higher cancer cell apoptosis with nearly 39% of cells in apoptosis chamber (early and late) compared to only ∼21% and ∼11% for CAP-loaded lipid nanoparticles (CLN) and CAP. The loading of drug in the lipid nanoparticle system extended the drug retention in the blood circulation and allowed the active targeting to specific cancer cells. The prolonged circulation of drug attributed to the antifouling property of polyethylene glycol molecule in the structure. Overall, study highlights that using targeting moiety could enhance the therapeutic response of nanomedicines in the treatment of solid tumors.

Factors pivotal for designing of nanoantimicrobials: an exposition

Understanding the interplay between bacterial pathogens and antimicrobials is a key to realize the control over infections causing morbidity and mortality. An important current issue of contemporary medicine and microbiology is the search for new strategies for adequate therapy of infectious diseases associated with rapidly emerging multidrug-resistant (MDR) pathogens. Recently, a great deal of progress has been made in the field of nanobiotechnology towards the development of various nanoantimicrobials (NAMs) as novel therapeutic solution. Current microbiological studies, employing either synthetic antibiotics or natural antimicrobial, have demonstrated the ability of NAMs to tackle the issue of MDR by reverting the mechanisms of resistance. The present review critically discusses the various factors that can contribute to modulate the effects of NAMs on microbes. It includes essential features of NAMs including but not limited to composition, surface charge, loading capacity, size, hydrophobicity/philicity, controlled release and functionalization. In contrast, how microbial structural differences, biofilm formation, persister cells and intracellular pathogens contribute towards sensitivity or resistance towards antimicrobials is comprehensively analysed. These multilateral factors should be considered earnestly in order to make NAMs a successful alternative of the conventional antibiotics.

Curcumin loaded mesoporous silica: an effective drug delivery system for cancer treatment

In the present study, we report the delivery of anti-cancer drug curcumin to cancer cells using mesoporous silica materials. A series of mesoporous silica material based drug delivery systems (S2, S4 and S6) were first designed and developed through the amine functionalization of KIT-6, MSU-2 and MCM-41 followed by the loading of curcumin. The curcumin loaded materials were characterized with several physico-chemical techniques and thoroughly screened on cancer cells to evaluate their in vitro drug delivery efficacy. All the curcumin loaded silica materials exhibited higher cellular uptake and inhibition of cancer cell viability compared to pristine curcumin. The effective internalization of curcumin in cancer cells through the mesoporous silica materials initiated the generation of intracellular reactive oxygen species and the down regulation of poly ADP ribose polymerase (PARP) enzyme levels compared to free curcumin leading to the activation of apoptosis. This study shows that the anti-cancer activity of curcumin can be potentiated by loading onto mesoporous silica materials. Therefore, we strongly believe that mesoporous silica based curcumin loaded drug delivery systems may have future potential applications for the treatment of cancers.

Perfluorocyclobutyl Aryl Ether-Based ABC Amphiphilic Triblock Copolymer

A series of fluorine-containing amphiphilic ABC triblock copolymers comprising hydrophilic poly(ethylene glycol) (PEG) and poly(methacrylic acid) (PMAA), and hydrophobic poly(p-(2-(4-biphenyl)perfluorocyclobutoxy)phenyl methacrylate) (PBPFCBPMA) segments were synthesized by successive atom transfer radical polymerization (ATRP). First, PEG-Br macroinitiators bearing one terminal ATRP initiating group were prepared by chain-end modification of monohydroxy-terminated PEG via esterification reaction. PEG-b-PBPFCBPMA-Br diblock copolymers were then synthesized via ATRP of BPFCBPMA monomer initiated by PEG-Br macroinitiator. ATRP polymerization of tert-butyl methacrylate (tBMA) was directly initiated by PEG-b-PBPFCBPMA-Br to provide PEG-b-PBPFCBPMA-b-PtBMA triblock copolymers with relatively narrow molecular weight distributions (M_w/M_n ≤ 1.43). The pendant tert-butyoxycarbonyls were hydrolyzed to carboxyls in acidic environment without affecting other functional groups for affording PEG-b-PBPFCBPMA-b-PMAA amphiphilic triblock copolymers. The critical micelle concentrations (cmc) were determined by fluorescence spectroscopy using N-phenyl-1-naphthylamine as probe and the self-assembly behavior in aqueous media were investigated by transmission electron microscopy. Large compound micelles and bowl-shaped micelles were formed in neutral aqueous solution. Interestingly, large compound micelles formed by triblock copolymers can separately or simultaneously encapsulate hydrophilic Rhodamine 6G and hydrophobic pyrene agents.

Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe@Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe@Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe@Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe@Au) nanoparticles and radiolabeled with 131I to combine magnetic targeted drug delivery and radiotherapy. Fe@Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe@Au nanoparticles (Fe@Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe@Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

Nanomedicine in Central Nervous System (CNS) Disorders: A Present and Future Prospective

Purpose: For the past few decades central nervous system disorders were considered as a major strike on human health and social system of developing countries. The natural therapeutic methods for CNS disorders limited for many patients. Moreover, nanotechnology-based drug delivery to the brain may an exciting and promising platform to overcome the problem of BBB crossing. In this review, first we focused on the role of the blood-brain barrier in drug delivery; and second, we summarized synthesis methods of nanomedicine and their role in different CNS disorder. Method: We reviewed the PubMed databases and extracted several kinds of literature on neuro nanomedicines using keywords, CNS disorders, nanomedicine, and nanotechnology. The inclusion criteria included chemical and green synthesis methods for synthesis of nanoparticles encapsulated drugs and, their in-vivo and in-vitro studies. We excluded nanomedicine gene therapy and nanomaterial in brain imaging. Results: In this review, we tried to identify a highly efficient method for nanomedicine synthesis and their efficacy in neuronal disorders. SLN and PNP encapsulated drugs reported highly efficient by easily crossing BBB. Although, these neuro-nanomedicine play significant role in therapeutics but some metallic nanoparticles reported the adverse effect on developing the brain. Conclusion: Although impressive advancement has made via innovative potential drug development, but their efficacy is still moderate due to limited brain permeability. To overcome this constraint,powerful tool in CNS therapeutic intervention provided by nanotechnology-based drug delivery methods. Due to its small and biofunctionalization characteristics, nanomedicine can easily penetrate and facilitate the drug through the barrier. But still, understanding of their toxicity level, optimization and standardization are a long way to go.

In vitro models for evaluating safety and efficacy of novel technologies for skin drug delivery

For preclinical testing of novel therapeutics, predictive in vitro models of the human skin are required to assess efficacy, absorption and safety. Simple as well as more sophisticated three-dimensional organotypic models of the human skin emerged as versatile and powerful tools simulating healthy as well as diseased skin states. Besides addressing the demands of research and industry, such models serve as valid alternative to animal testing. Recently, the acceptance of several models by regulatory authorities corroborates their role as important building block for preclinical development. However, valid assessment of readout parameters derived from these models requires suitable analytical techniques. Standard analytical methods are mostly destructive and limited regarding in-depth investigation on molecular level. The combination of adequate in vitro models with modern non-invasive analytical modalities bears a great potential to address important skin drug delivery related questions. Topics of interest are for instance the assessment of repeated dosing effects and xenobiotic biotransformation, which cannot be analyzed by destructive techniques. This review provides a comprehensive overview of current in vitro skin models differing in functional complexity and mimicking healthy as well as diseased skin states. Further, benefits and limitations regarding analytical evaluation of efficacy, absorption and safety of novel drug carrier systems applied to such models are discussed along with a prospective view of anticipated future directions. In addition, emerging non-invasive imaging modalities are introduced and their significance and potential to advance current knowledge in the field of skin drug delivery is explored.