A targeted and adjuvanted nanocarrier lowers the effective dose of liposomal amphotericin B and enhances adaptive immunity in murine cutaneous leishmaniasis

Synthetic biology for combating leishmaniasis

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Despite the efforts to control and treat the disease, it still remains a major public health problem in many countries. Synthetic biology is a rapidly evolving interdisciplinary field that combines biology, engineering, and computer science to design and construct novel biological systems. In recent years, synthetic biology approaches have shown great promise for developing new and effective strategies to combat leishmaniasis. In this perspective, we summarize the recent advances in the use of synthetic biology for the development of vaccines, diagnostic tools, and novel therapeutics for leishmaniasis.

Immunogenicity of Recombinant Lipid-Based Nanoparticle Vaccines: Danger Signal vs. Helping Hand

Infectious diseases are a predominant problem in human health. While the incidence of many pathogenic infections is controlled by vaccines, some pathogens still pose a challenging task for vaccine researchers. In order to face these challenges, the field of vaccine development has changed tremendously over the last few years. For non-replicating recombinant antigens, novel vaccine delivery systems that attempt to increase the immunogenicity by mimicking structural properties of pathogens are already approved for clinical applications. Lipid-based nanoparticles (LbNPs) of different natures are vesicles made of lipid layers with aqueous cavities, which may carry antigens and other biomolecules either displayed on the surface or encapsulated in the cavity. However, the efficacy profile of recombinant LbNP vaccines is not as high as that of live-attenuated ones. This review gives a compendious picture of two approaches that affect the immunogenicity of recombinant LbNP vaccines: (i) the incorporation of immunostimulatory agents and (ii) the utilization of pre-existing or promiscuous cellular immunity, which might be beneficial for the development of tailored prophylactic and therapeutic LbNP vaccine candidates.

A Systematic Review of Drug-Carrying Nanosystems Used in the Treatment of Leishmaniasis

Leishmaniasis is an infectious disease responsible for a huge rate of morbidity and mortality in humans. Chemotherapy consists of the use of pentavalent antimonial, amphotericin B, pentamidine, miltefosine, and paromomycin. However, these drugs are associated with some drawbacks such as high toxicity, administration by parenteral route, and most seriously the resistance of some strains of the parasite to them. Several strategies have been used to increase the therapeutic index and reduce the toxic effects of these drugs. Among them, the use of nanosystems that have great potential as a site-specific drug delivery system stands out. This review aims to compile results from studies that were carried out using first- and second-line antileishmanial drug-carrying nanosystems. The articles referred to here were published between 2011 and 2021. This study shows the promise of effective applicability of drug-carrying nanosystems in the field of antileishmanial therapeutics, with the perspective of providing better patient adherence to treatment, increased therapeutic efficacy, reduced toxicity of conventional drugs, as well as the potential to efficiently improve the treatment of leishmaniasis.

Peptide-Functionalized Dendrimer Nanocarriers for Targeted Microdystrophin Gene Delivery

Gene therapy is a good alternative for determined congenital disorders; however, there are numerous limitations for gene delivery in vivo including targeted cellular uptake, intracellular trafficking, and transport through the nuclear membrane. Here, a modified G5 polyamidoamine (G5 PAMAM) dendrimer-DNA complex was developed, which will allow cell-specific targeting to skeletal muscle cells and transport the DNA through the intracellular machinery and the nuclear membrane. The G5 PAMAM nanocarrier was modified with a skeletal muscle-targeting peptide (SMTP), a DLC8-binding peptide (DBP) for intracellular transport, and a nuclear localization signaling peptide (NLS) for nuclear uptake, and polyplexed with plasmid DNA containing the GFP-tagged microdystrophin (µDys) gene. The delivery of µDys has been considered as a therapeutic modality for patients suffering from a debilitating Duchenne muscular dystrophy (DMD) disorder. The nanocarrier-peptide-DNA polyplexes were prepared with different charge ratios and characterized for stability, size, surface charge, and cytotoxicity. Using the optimized nanocarrier polyplexes, the transfection efficiency in vitro was determined by demonstrating the expression of the GFP and the µDys protein using fluorescence and Western blotting studies, respectively. Protein expression in vivo was determined by injecting an optimal nanocarrier polyplex formulation to Duchenne model mice, mdx^4Cv. Ultimately, these nanocarrier polyplexes will allow targeted delivery of the microdystrophin gene to skeletal muscle cells and result in improved muscle function in Duchenne muscular dystrophy patients.

Nanotechnology-aided diagnosis, treatment and prevention of leishmaniasis

Leishmaniasis is a prevalent parasitic infection belonging to neglected tropical diseases. It is caused by Leishmania protozoan parasites transmitted by sandflies and it is responsible for increased morbidity/mortality especially in low- and middle-income countries. The lack of cheap, portable, easy to use diagnostic tools exhibiting high efficiency and specificity impede the early diagnosis of the disease. Furthermore, the typical anti-leishmanial agents are cytotoxic, characterized by low patient compliance and require long-term regimen and usually hospitalization. In addition, due to the intracellular nature of the disease, the existing treatments exhibit low bioavailability resulting in low therapeutic efficacy. The above, combined with the common development of resistance against the anti-leishmanial agents, denote the urgent need for novel therapeutic strategies. Furthermore, the lack of effective prophylactic vaccines hinders the control of the disease. The development of nanoparticle-based biosensors and nanocarrier-aided treatment and vaccination strategies could advance the diagnosis, therapy and prevention of leishmaniasis. The present review intends to highlight the various nanotechnology-based approaches pursued until now to improve the detection of Leishmania species in biological samples, decrease the side effects and increase the efficacy of anti-leishmanial drugs, and induce enhanced immune responses, specifically focusing on the outcome of their preclinical and clinical evaluation.

Developments in Treatment Methodologies Using Dendrimers for Infectious Diseases

Dendrimers comprise a specific group of macromolecules, which combine structural properties of both single molecules and long expanded polymers. The three-dimensional form of dendrimers and the extensive possibilities for use of additional substrates for their construction creates a multivalent potential and a wide possibility for medical, diagnostic and environmental purposes. Depending on their composition and structure, dendrimers have been of interest in many fields of science, ranging from chemistry, biotechnology to biochemical applications. These compounds have found wide application from the production of catalysts for their use as antibacterial, antifungal and antiviral agents. Of particular interest are peptide dendrimers as a medium for transport of therapeutic substances: synthetic vaccines against parasites, bacteria and viruses, contrast agents used in MRI, antibodies and genetic material. This review focuses on the description of the current classes of dendrimers, the methodology for their synthesis and briefly drawbacks of their properties and their use as potential therapies against infectious diseases.

Application of Dendrimers for Treating Parasitic Diseases

Despite advances in medical knowledge, parasitic diseases remain a significant global health burden and their pharmacological treatment is often hampered by drug toxicity. Therefore, drug delivery systems may provide useful advantages when used in combination with conventional therapeutic compounds. Dendrimers are three-dimensional polymeric structures, characterized by a central core, branches and terminal functional groups. These nanostructures are known for their defined structure, great water solubility, biocompatibility and high encapsulation ability against a wide range of molecules. Furthermore, the high ratio between terminal groups and molecular volume render them a hopeful vector for drug delivery. These nanostructures offer several advantages compared to conventional drugs for the treatment of parasitic infection. Dendrimers deliver drugs to target sites with reduced dosage, solving side effects that occur with accepted marketed drugs. In recent years, extensive progress has been made towards the use of dendrimers for therapeutic, prophylactic and diagnostic purposes for the management of parasitic infections. The present review highlights the potential of several dendrimers in the management of parasitic diseases.

Peptide-Modified Biopolymers for Biomedical Applications

Polymeric biomaterials have been used in a variety of applications, like cargo delivery and tissue scaffolding, because they are easily synthesized and can be adapted to many systems. However, there is still a need to further enhance and improve their functions to progress their use in the biomedical field. A promising solution is to modify the polymer surfaces with peptides that can increase biocompatibility, cellular interactions, and receptor targeting. In recent years, peptide modifications have been used to overcome many challenges to polymer biomaterial development. This review discusses recent progress in developing peptide-modified polymers for therapeutic applications including cell-specific targeting and tissue engineering. Furthermore, we will explore some of the most frequently studied base components of these biomaterials.

Dendrimers against fungi - A state of the art review

Fungal based diseases currently affect nearly a quarter of the population around the world, which diseases are usually limited to superficial infections. Perversely, along with the development of modern medicine, cases of life-threatening systemic fungi are more and more often encountered. Compared to antibacterial drugs, significantly fewer fungicides are tested and introduced to clinical practice. At the same time, the drug resistance of pathological fungi is constantly growing. In addition to obtaining new derivatives of already-established classes of drugs, such as azoles, there is a growing interest in new compounds with potentially new mechanisms and application possibilities. Polymers are included in the flow of these studies, and among them - dendrimers. Dendrimers are a special type of polymers with a strictly defined structure and a plethora of functionalization possibilities. This allows them to not only be used as effective antifungal drug carriers but also enables them to exhibit antifungal activity per se. In this review, we have introduced to the epidemiology of fungal infections and summarized the aspects related to their control and therapy. Various polymers and dendrimers with antifungal activity were presented. In the subsequent sections antifungal acting dendrimers were discussed within three subchapters, based on their chemical structure: (i) amino acid-based dendrimers, (ii) amino based dendrimers, and (iii) other, which do not share similarities in structure. We have gathered and summarized the reports regarding the direct action of dendrimers on infectious fungi, as well as their effect when used as solubilizers, carriers or adjuvants with currently used antifungals. Use of dendrimers for the sensing of fungi or their metabolites are also considered. Special attention was also paid to the applications of dendrimers together with photosensitizers in antimicrobial photodynamic therapy.

Vaccination against cocaine using a modifiable dendrimer nanoparticle platform

Pharmacological therapies for the treatment of cocaine addiction have had disappointing efficacy, and the lack of recent developments in the clinical care of cocaine-addicted patients indicates a need for novel treatment strategies. Recent studies have shown that vaccination against cocaine to elicit production of antibodies that reduce concentrations of free drug in the blood is a promising method to protect against the effects of cocaine and reduce rates of relapse. However, the poorly immunogenic nature of cocaine remains a major hurdle to active immunization. Therefore, we hypothesized that strategies to increase targeted exposure of cocaine to the immune system may produce a more effective vaccine. To specifically direct an immune response against cocaine, in the present study we have conjugated a cocaine analog to a dendrimer-based nanoparticle carrier with MHC II-binding moieties that previously has been shown to activate antigen-presenting cells necessary for antibody production. This strategy produced a rapid, prolonged, and high affinity anti-cocaine antibody response without the need for an adjuvant. Surprisingly, additional evaluation using multiple adjuvant formulations in two strains of inbred mice found adjuvants were either functionally redundant or deleterious in the vaccination against cocaine using this platform. The use of conditioned place preference in rats after administration of this vaccine provided proof of concept for the ability of this vaccine to diminish cocaine reward. Together these data demonstrate the intrinsic efficacy of an immune-targeting dendrimer-based cocaine vaccine, with a vast potential for design of future vaccines against other poorly immunogenic antigens by substitution of the conjugated cargo.

Protective Cellular Immune Response Induction for Cutaneous Leishmaniasis by a New Immunochemotherapy Schedule

The palladacycle complex DPPE 1.2 was previously shown to inhibit Leishmania (Leishmania) amazonensis infection in vitro and in vivo. The present study aimed to evaluate the effect of DPPE 1.2 associated with a recombinant cysteine proteinase, rLdccys1, and the adjuvant Propionibacterium acnes on L. (L.) amazonensis infection in two mouse strains, BALB/c, and C57BL/6. Treatment with this association potentiated the leishmanicidal effect of DPPE 1.2 resulting in a reduction of parasite load in both strains of mice which was higher compared to that found in groups treated with either DPPE 1.2 alone or associated with P. acnes or rLdccys1. The reduction of parasite load in both mice strains was followed by immunomodulation mediated by an increase of memory CD4⁺ and CD8⁺ T lymphocytes, IFN-γ levels and reduction of active TGF-β in treated animals. No infection relapse was observed 1 month after the end of treatment in mice which received DPPE 1.2 associated with rLdccys1 or rLdccys1 plus P. acnes in comparison to that exhibited by animals treated with DPPE 1.2 alone. Evaluation of serum levels of AST, ALT, urea, and creatinine showed no alterations among treated groups, indicating that this treatment schedule did not induce hepato or nephrotoxicity. These data indicate the potential use of this association as a therapeutic alternative for cutaneous leishmaniasis caused by L. (L) amazonensis.

Comparative analysis between four model nanoformulations of amphotericin B-chitosan, amphotericin B-dendrimer, betulinic acid-chitosan and betulinic acid-dendrimer for treatment of Leishmania major: real-time PCR assay plus

Background

Amphotericin B (Amp) and Betulinic acid (BA) as antileishmanial agents have negligible water solubility and high toxicity. To solve these problems, for the first time, chitosan nanoparticles and Anionic Linear Globular Dendrimer (D) were synthesized for the treatment of Leishmania major (L. major).

Method

Chitosan and dendrimer nanoparticles were synthesized, and Amp and BA were loaded into the nanoparticles. The particles were then characterized using various methods and their efficacy was evaluated in vitro and in vivo environments (parasite burden was confirmed using pathological studies and real-time PCR methods).

Result

The results of docking showed that Amp and BA can be loaded into chitosan and dendrimer nanoparticles. The results of physically drug loading efficiency for AK (Amphotericin B-chitosan), BK (Betulinic acid-chitosan), AD (Amphotericin B-Dendrimer) and BD (Betulinic acid- Dendrimer) were 90, 93, 84 and 96 percent, respectively. The characterization results indicated that the drugs were loaded into nanoparticles physically. Moreover, the increased solubility rate for AD=478, BD=790, AK=80 and BK=300 folds. Furthermore, the results of the drug delivery system showed the slow controlled drug release pattern with cellular uptake of more than 90%. The treatment results showed a 100 percent decrease of toxicity for the all nanodrugs was observed in vivo and in vitro environments. Moreover, AK10 and BK20 mg/kg reduced parasite burden by 83 percent (P<0.001), while AD50 and BD40 mg/kg reduced it to a lesser extent compared to glucantime.

Conclusion

All the synthesized nanodrugs were completely succeeded by 100% to recovery the L. major induced pathological effects in the infected footpad. Also, the results of present study were confirmed with real-time PCR and the results showed that AK and BK were succeeded in a large extent to the treatment of L. major infection (P<0.001), therefore AK and BK could be considered as proper alternatives of choices drugs.

Innovative Solutions for the Control of Leishmaniases: Nanoscale Drug Delivery Systems

Background:

Leishmania are sandfly-transmitted protozoan parasites that harbour within the macrophages of a mammalian host and cause leishmaniasis, a serious zoonotic disease that threatens the lives of millions worldwide. Its numerous forms (cutaneous, mucocutaneous, and visceral) are currently treated with a sparse arsenal of drugs, specifically antimonials, amphotericin B, miltefosine, and paromomycin, for which drug resistance and clinical failure are rampant. Medicine is presently trending towards nanotechnology to aid in the successful delivery of drugs. Vehicles such as lipid-based nanocarriers, polymer-based nanoparticles, and metal ions and oxides have been previously demonstrated to improve bioavailability of drugs and decrease toxicity for the patient. These cutting-edge solutions can be combined with existing active molecules, as well as novel drugs or plant extracts with promising antileishmanial activity.

Conclusion:

This review explores the current evidence for the treatment of leishmaniases using nanoscale drug delivery systems (specifically lipid-, polymer- and metal-based systems) and encourages further development of the aforementioned nanotechnologies for treatment of Leishmania.

Nanocarrier-based systems for wound healing

In general, the systems intended for the treatment and recovery of wounds, seek to act as a coating for the damaged area, maintaining an adequate level of humidity, reducing pain, and preventing the invasion and proliferation of microorganisms. Although many of the systems that are currently on the market meet the purposes mentioned above, with the arrival of nanotechnology, it has sought to improve the performance of these coatings. The variety of nano-systems that have been proposed is very extensive, including the use of very different materials (natural or synthetic) ranging from polymers or lipids to systems derived from microorganisms. With the objective of improving the performance of the systems, seeking to combat several of the problems that arise in a wound, especially when it is chronic, these materials have been combined, giving rise to nanocomposites or scaffolds. In recent years, the interest in the development of systems for the treatment of wounds is notable, which is reflected in the increase in publications related to the subject. Therefore, this document presents generalities of systems involving nanocarriers, mentioning some examples of representative systems of each case.

Exploiting knowledge on pharmacodynamics-pharmacokinetics for accelerated anti-leishmanial drug discovery/development

Introduction: Being on the top list of neglected tropical diseases, leishmaniasis has been marked for elimination by 2020. In the light of small armamentarium of drugs and their associated drawbacks, the understanding of pharmacodynamics and/or pharmacokinetics becomes a priority to achieve and sustain disease elimination. Areas covered: The authors have looked into pharmacological aspects of existing and emerging drugs for treatment of leishmaniasis. An in-depth understanding of pharmacodynamics and pharmacokinetics (PKPD) provides a rationale for drug designing and optimizing the treatment strategies. It forms a key to prevent drug resistance and avoid drug-associated adverse effects. The authors have compiled the researches on the PKPD of different anti-leishmanial formulations that have the potential for improved and/or effective disease intervention. Expert opinion: Understanding the pharmacological aspects of drugs forms the basis for the clinical application of novel drugs. Tailoring drug dosage and individualized treatment can avoid the adverse events and bridge gap between the in vitro models and their clinical application. An integrated approach, with pragmatic use of technological advances can improve phenotypic screening and physiochemical properties of novel drugs. Concomitantly, this can serve to improve clinical efficacies, reduce the incidence of relapse and accelerate the drug discovery/development process for leishmaniasis elimination.

Application of Dendrimers for the Treatment of Infectious Diseases

Dendrimers are drug delivery systems that are characterized by a three-dimensional, star-shaped, branched macromolecular network. They possess ideal properties such as low polydispersity index, biocompatibility and good water solubility. They are made up of the interior and the exterior layers. The exterior layer consists of functional groups that are useful for conjugation of drugs and targeting moieties. The interior layer exhibits improved drug encapsulation efficiency, reduced drug toxicity, and controlled release mechanisms. These unique properties make them useful for drug delivery. Dendrimers have attracted considerable attention as drug delivery system for the treatment of infectious diseases. The treatment of infectious diseases is hampered severely by drug resistance. Several properties of dendrimers such as their ability to overcome drug resistance, toxicity and control the release mechanism of the encapsulated drugs make them ideal systems for the treatment of infectious disease. The aim of this review is to discuss the potentials of dendrimers for the treatment of viral and parasitic infections.

Reduction toxicity of Amphotericin B through loading into a novel nanoformulation of anionic linear globular dendrimer for improve treatment of leishmania major

Amphotericin B (A) as an antileishmanial drug has limited clinical application owing to severe side-effects and low-water solubility. This is the first study reported using Anionic Linear Globular Dendrimer (ALGD) as A carrier for the increase of A solubility rate, decrease its toxicity, and improve its therapeutic effects. ALGD was synthesized and A was loaded into nanoparticles for the first time with the drug-loading efficiency of 82%. Drug loading was confirmed using characterization methods. The drug solubility rate was increased by 478-folds. The results of the study showed that the A toxicity was significantly decreased by 95% in vitro and in vivo environments, which was confirmed by pathology findings and enzymatic evaluation. Furthermore, the nanodrug caused that mortality rate was reached to zero. Moreover, the nanodrug was as potent as the free drug and glucantime (GUL) in reducing the parasite burden and parasite number. These findings indicated the potency of ALGD to decrease the drug side-effects, increase the drug solubility rate, and improve the drug efficacy. Moreover, the nanoformulation was a non-toxic and cost-effective formulation. The conformity between in vitro and in vivo results suggested that the A-loaded ALGD could be considered as a promising candidate in reducing the side-effects of A in leishmaniasis treatment.

Function Oriented Molecular Design: Dendrimers as Novel Antimicrobials

In recent years innovative nanostructures are attracting increasing interest and, among them, dendrimers have shown several fields of application. Dendrimers can be designed and modified in plentiful ways giving rise to hundreds of different molecules with specific characteristics and functionalities. Biomedicine is probably the field where these molecules find extraordinary applicability, and this is probably due to their multi-valency and to the fact that several other chemicals can be coupled to them to obtain desired compounds. In this review we will describe the different production strategies and the tools and technologies for the study of their characteristics. Finally, we provide a panoramic overview of their applications to meet biomedical needs, especially their use as novel antimicrobials.

4PD Functionalized Dendrimers: A Flexible Tool for In Vivo Gene Silencing of Tumor-Educated Myeloid Cells

Myeloid cells play a key role in tumor progression and metastasis by providing nourishment and immune protection, as well as facilitating cancer invasion and seeding to distal sites. Although advances have been made in understanding the biology of these tumor-educated myeloid cells (TEMCs), their intrinsic plasticity challenges our further understanding of their biology. Indeed, in vitro experiments only mimic the in vivo setting, and current gene-knockout technologies do not allow the simultaneous, temporally controlled, and cell-specific silencing of multiple genes or pathways. In this article, we describe the 4PD nanoplatform, which allows the in vivo preferential transfection and in vivo tracking of TEMCs with the desired RNAs. This platform is based on the conjugation of CD124/IL-4Rα-targeting peptide with G5 PAMAM dendrimers as the loading surface and can convey therapeutic or experimental RNAs of interest. When injected i.v. in mice bearing CT26 colon carcinoma or B16 melanoma, the 4PD nanoparticles predominantly accumulate at the tumor site, transfecting intratumoral myeloid cells. The use of 4PD to deliver a combination of STAT3- and C/EBPβ-specific short hairpin RNA or miR-142-3p confirmed the importance of these genes and microRNAs in TEMC biology and indicates that silencing of both genes is necessary to increase the efficacy of immune interventions. Thus, the 4PD nanoparticle can rapidly and cost effectively modulate and assess the in vivo function of microRNAs and mRNAs in TEMCs.

Nanoparticles as safe and effective delivery systems of antifungal agents: Achievements and challenges

Invasive fungal infections are becoming a major health concern in several groups of patients leading to severe morbidity and mortality. Moreover, cutaneous fungal infections are a major cause of visits to outpatient dermatology clinics. Despite the availability of several effective agents in the antifungal drug arena, their therapeutic outcome is less than optimal due to limitations related to drug physicochemical properties and toxicity. For instance, poor aqueous solubility limits the formulation options and efficacy of several azole antifungal drugs while toxicity limits the benefits of many other drugs. Nanoparticles hold great promise to overcome these limitations due to their ability to enhance drug aqueous solubility, bioavailability and antifungal efficacy. Further, drug incorporation into nanoparticles could greatly reduce its toxicity. Despite these interesting nanoparticle features, there are only few marketed nanoparticle-based antifungal drug formulations. This review sheds light on different classes of nanoparticles used in antifungal drug delivery, such as lipid-based vesicles, polymeric micelles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and dendrimers with emphasis on their advantages and limitations. Translation of these nanoformulations from the lab to the clinic could be facilitated by focusing the research on overcoming problems related to nanoparticle stability, drug loading and high cost of production and standardization.

Directing and Potentiating Stem Cell-Mediated Angiogenesis and Tissue Repair by Cell Surface E-Selectin Coating

Stem cell therapy has emerged as a promising approach for treatment of a number of diseases, including delayed and non-healing wounds. However, targeted systemic delivery of therapeutic cells to the dysfunctional tissues remains one formidable challenge. Herein, we present a targeted nanocarrier-mediated cell delivery method by coating the surface of the cell to be delivered with dendrimer nanocarriers modified with adhesion molecules. Infused nanocarrier-coated cells reach to destination via recognition and association with the counterpart adhesion molecules highly or selectively expressed on the activated endothelium in diseased tissues. Once anchored on the activated endothelium, nanocarriers-coated transporting cells undergo transendothelial migration, extravasation and homing to the targeted tissues to execute their therapeutic role. We now demonstrate feasibility, efficacy and safety of our targeted nanocarrier for delivery of bone marrow cells (BMC) to cutaneous wound tissues and grafted corneas and its advantages over conventional BMC transplantation in mouse models for wound healing and neovascularization. This versatile platform is suited for targeted systemic delivery of virtually any type of therapeutic cell.

New approaches from nanomedicine for treating leishmaniasis

This review summarizes the recent progress in nanomedicine for the treatment of leishmaniasis.

Nanoparticles for Fidgety Cell Movement and Enhanced Wound Healing

Complex spatiotemporal interaction of Rho GTPases with microtubules (MTs) and MT-associated proteins drives directed cellular migration. In this issue, Charafeddine et al. describe a role for a novel MT-severing enzyme, fidgetin-like 2 (FL2), in directional migration of keratinocytes and fibroblasts. FL2 normally localizes to the leading edge of the cell cortex where it shears MTs, thus dictating the size and distribution of focal adhesions by regulating cytoskeletal remodeling. Small interfering RNA (siRNA)-directed knockdown of FL2 increases cell migration and focal adhesion area in vitro through possible interaction with Rho GTPases. Efficient FL2 knockdown in murine wounds was achieved using nanoparticles as a siRNA delivery vehicle, and this resulted in enhanced wound closure in vivo. Effective siRNA nanoparticle targeting of MT-severing enzymes offers promise of controlled and targeted delivery that may maximize therapeutic success for patients with burn wounds and chronic wound disorders.

Adjuvant cationic liposomes presenting MPL and IL-12 induce cell death, suppress tumor growth, and alter the cellular phenotype of tumors in a murine model of breast cancer

Dendritic cells (DC) process and present antigens to T lymphocytes, inducing potent immune responses when encountered in association with activating signals, such as pathogen-associated molecular patterns. Using the 4T1 murine model of breast cancer, cationic liposomes containing monophosphoryl lipid A (MPL) and interleukin (IL)-12 were administered by intratumoral injection. Combination multivalent presentation of the Toll-like receptor-4 ligand MPL and cytotoxic 1,2-dioleoyl-3-trmethylammonium-propane lipids induced cell death, decreased cellular proliferation, and increased serum levels of IL-1β and tumor necrosis factor (TNF)-α. The addition of recombinant IL-12 further suppressed tumor growth and increased expression of IL-1β, TNF-α, and interferon-γ. IL-12 also increased the percentage of cytolytic T cells, DC, and F4/80(+) macrophages in the tumor. While single agent therapy elevated levels of nitric oxide synthase 3-fold above basal levels in the tumor, combination therapy with MPL cationic liposomes and IL-12 stimulated a 7-fold increase, supporting the observed cell cycle arrest (loss of Ki-67 expression) and apoptosis (TUNEL positive). In mice bearing dual tumors, the growth of distal, untreated tumors mirrored that of liposome-treated tumors, supporting the presence of a systemic immune response.

Drug delivery: lessons to be learnt from Leishmania studies

Background Leishmaniasis is a disease caused by infection with the protozoan parasite Leishmania, which is responsible for three main types of disease: cutaneous leishmaniasis, visceral leishmaniasis and mucocutaneous leishmaniasis based to the site of infection for the particular species. This presents a major challenge to successful drug treatment, as a drug must not only reach antileishmanial concentrations in infected macrophages, the parasites' host cell, but also reach infected cells in locations specific to the type of disease. In this paper we discuss how studies using Leishmania have contributed to our knowledge on how drug delivery systems can be used to improve drug efficacy and delivery.

Immunomodulation of nanoparticles in nanomedicine applications

Nanoparticles (NPs) have promising applications in medicine. Immune system is an important protective system to defend organisms from non-self matters. NPs interact with the immune system and modulate its function, leading to immunosuppression or immunostimulation. These modulating effects may bring benefits or danger. Compositions, sizes, and surface chemistry, and so forth, affect these immunomodulations. Here we give an overview of the relationship between the physicochemical properties of NPs, which are candidates to be applied in medicine, and their immunomodulation properties.