Turning an antiviral into an anticancer drug: nanoparticle delivery of acyclovir monophosphate

Clinical efficacy of washed microbiota transplantation on metabolic syndrome and metabolic profile of donor outer membrane vesicles

Object

To clarify the clinical efficacy of washed microbiota transplantation (WMT) for metabolic syndrome (MetS), and explore the differences in the metabolic profile of bacterial outer membrane vesicles (OMVs) in donor fecal bacteria suspension received by MetS patients with good and poor outcomes, and to construct a predictive model for the efficacy of WMT for MetS using differential metabolites.

Methods

Medical data 65 MetS patients who had completed at least 2 courses of WMT from 2017.05 to 2023.07 were collected. Fecal bacteria suspension of WMT donors were collected, and the clinical data of MetS patients treated with WMT during this period were collected as well. The changes of BMI, blood glucose, blood lipids, blood pressure and other indicators before and after WMT were compared. OMVs were isolated from donor fecal bacteria suspension and off-target metabolomic sequencing was performed by Liquid Chromatograph Mass Spectrometer (LC-MS).

Results

Compared with baseline, Body mass index (BMI), Systolic blood pressure (SBP) and Diastolic blood pressure (DBP) of MetS patients showed significant decreases after the 1st (short-term) and 2nd (medium-term) courses, and fasting blood glucose (FBG) also showed significant decreases after the 1st session. There was a significant difference between the Marked Response OMVs and the Moderate Response OMVs. It was showed that 960 metabolites were significantly up-regulated in Marked Response OMVs and 439 metabolites that were significantly down-regulated. The ROC model suggested that 9-carboxymethoxymethylguanine, AUC = 0.8127, 95% CI [0.6885, 0.9369], was the most potent metabolite predicting the most available metabolite for efficacy.

Conclusion

WMT had significant short-term and medium-term clinical efficacy in MetS. There were differences in the structure of metabolites between Marked Response OMVs and Moderate Response OMVs. The level of 9-Carboxy methoxy methylguanine in Marked Response OMVs can be a good predictor of the efficacy of WMT in the treatment of MetS.

Recent Advances in the Synthesis of Acyclic Nucleosides and Their Therapeutic Applications

DNA is commonly known as the "molecule of life" because it holds the genetic instructions for all living organisms on Earth. The utilization of modified nucleosides holds the potential to transform the management of a wide range of human illnesses. Modified nucleosides and their role directly led to the 2023 Nobel prize. Acyclic nucleosides, due to their distinctive physiochemical and biological characteristics, rank among the most adaptable modified nucleosides in the field of medicinal chemistry. Acyclic nucleosides are more resistant to chemical and biological deterioration, and their adaptable acyclic structure makes it possible for them to interact with various enzymes. A phosphonate group, which is linked via an aliphatic functionality to a purine or a pyrimidine base, distinguishes acyclic nucleoside phosphonates (ANPs) from other nucleotide analogs. Acyclic nucleosides and their derivatives have demonstrated various biological activities such as anti-viral, anti-bacterial, anti-cancer, anti-microbial, etc. Ganciclovir, Famciclovir, and Penciclovir are the acyclic nucleoside-based drugs approved by FDA for the treatment of various diseases. Thus, acyclic nucleosides are extremely useful for generating a variety of unique bioactive chemicals. Their biological activities as well as selectivity is significantly influenced by the stereochemistry of the acyclic nucleosides because chiral acyclic nucleosides have drawn a lot of interest due to their intriguing biological functions and potential as medicines. For example, tenofovir's (R) enantiomer is roughly 50 times more potent against HIV than its (S) counterpart. We can confidently state, "The most promising developments are yet to come in the realm of acyclic nucleosides!" Herein, we have covered the most current developments in the field of chemical synthesis and therapeutic applications of acyclic nucleosides based upon our continued interest and activity in this field since mid-1990's.

ACV with/without IVM: a new talk on intestinal CDX2 and muscular CD34 and Cyclin D1 during Trichinella spiralis infection

The current study assessed the efficacy of Acyclovir (ACV) and Ivermectin (IVM) as monotherapies and combined treatments for intestinal and muscular stages of Trichinella spiralis infection. One-hundred Swiss albino mice received orally 250 ± 50 infectious larvae and were divided into infected-untreated (Group-1), IVM-treated (Group-2), ACV-treated (Group-3), combined IVM+ACV (Group-4), and healthy controls (Group-5). Each group was subdivided into subgroup-A-enteric phase (10 mice, sacrificed day-7 p.i.) and subgroup-B-muscular phase (10 mice, sacrificed day-35 p.i.). Survival rate and body weight were recorded. Parasite burden and intestinal histopathology were assessed. In addition, immunohistochemical expression of epithelial CDX2 in the intestinal phase and CyclinD1 as well as CD34 in the muscular phase were evaluated. Compared, IVM and ACV monotherapies showed insignificant differences in the amelioration of enteric histopathology, except for lymphocytic counts. In the muscle phase, monotherapies showed variable disruptions in the encapsulated larvae. Compared with monotherapies, the combined treatment performed relatively better improvement of intestinal inflammation and reduction in the enteric and muscular parasite burden. CDX2 and CyclinD1 positively correlated with intestinal inflammation and parasite burden, while CD34 showed a negative correlation. CDX2 positively correlated with CyclinD1. CD34 negatively correlated with CDX2 and CyclinD1. IVM +ACV significantly ameliorated CDX2, CyclinD1, and CD34 expressions compared with monotherapies. Conclusion. T. spiralis infection-associated inflammation induced CDX2 and CyclinD1 expressions, whereas CD34 was reduced. The molecular tumorigenic effect of the nematode remains questionable. Nevertheless, IVM +ACV appeared to be a promising anthelminthic anti-inflammatory combination that, in parallel, rectified CDX2, CyclinD1, and CD34 expressions.

Incorporation of N7-Platinated Guanines into Thermus Aquaticus (Taq) DNA Polymerase: Atomistic Insights from Molecular Dynamics Simulations

In this work, we elucidated some key aspects of the mechanism of action of the cisplatin anticancer drug, cis-[Pt(NH₃)₂Cl₂], involving direct interactions with free nucleotides. A comprehensive in silico molecular modeling analysis was conducted to compare the interactions of Thermus aquaticus (Taq) DNA polymerase with three distinct N7-platinated deoxyguanosine triphosphates: [Pt(dien)(N7-dGTP)] (1), cis-[Pt(NH₃)₂Cl(N7-dGTP)] (2), and cis-[Pt(NH₃)₂(H₂O)(N7-dGTP)] (3) {dien = diethylenetriamine; dGTP = 5'-(2'-deoxy)-guanosine-triphosphate}, using canonical dGTP as a reference, in the presence of DNA. The goal was to elucidate the binding site interactions between Taq DNA polymerase and the tested nucleotide derivatives, providing valuable atomistic insights. Unbiased molecular dynamics simulations (200 ns for each complex) with explicit water molecules were performed on the four ternary complexes, yielding significant findings that contribute to a better understanding of experimental results. The molecular modeling highlighted the crucial role of a specific α-helix (O-helix) within the fingers subdomain, which facilitates the proper geometry for functional contacts between the incoming nucleotide and the DNA template needed for incorporation into the polymerase. The analysis revealed that complex 1 exhibits a much lower affinity for Taq DNA polymerase than complexes 2-3. The affinities of cisplatin metabolites 2-3 for Taq DNA polymerase were found to be quite similar to those of natural dGTP, resulting in a lower incorporation rate for complex 1 compared to complexes 2-3. These findings could have significant implications for the cisplatin mechanism of action, as the high intracellular availability of free nucleobases might promote the competitive incorporation of platinated nucleotides over direct cisplatin attachment to DNA. The study's insights into the incorporation of platinated nucleotides into the Taq DNA polymerase active site suggest that the role of platinated nucleotides in the cisplatin mechanism of action may have been previously underestimated.

Critical Review of Synthesis, Toxicology and Detection of Acyclovir

Acyclovir (ACV) is an effective and selective antiviral drug, and the study of its toxicology and the use of appropriate detection techniques to control its toxicity at safe levels are extremely important for medicine efforts and human health. This review discusses the mechanism driving ACV’s ability to inhibit viral coding, starting from its development and pharmacology. A comprehensive summary of the existing preparation methods and synthetic materials, such as 5-aminoimidazole-4-carboxamide, guanine and its derivatives, and other purine derivatives, is presented to elucidate the preparation of ACV in detail. In addition, it presents valuable analytical procedures for the toxicological studies of ACV, which are essential for human use and dosing. Analytical methods, including spectrophotometry, high performance liquid chromatography (HPLC), liquid chromatography/tandem mass spectrometry (LC-MS/MS), electrochemical sensors, molecularly imprinted polymers (MIPs), and flow injection–chemiluminescence (FI-CL) are also highlighted. A brief description of the characteristics of each of these methods is also presented. Finally, insight is provided for the development of ACV to drive further innovation of ACV in pharmaceutical applications. This review provides a comprehensive summary of the past life and future challenges of ACV.

Reconstituted high density lipoprotein (rHDL), a versatile drug delivery nanoplatform for tumor targeted therapy

rHDL is a synthesized drug delivery nanoplatform exhibiting excellent biocompatibility, which possesses most of the advantages of HDL. rHDL shows almost no toxicity and can be degraded to non-toxic substances in vivo. The severe limitation of the application of various antitumor agents is mainly due to their low bioavailability, high toxicity, poor stability, etc. Favorably, antitumor drug-loaded rHDL nanoparticles (NPs), which are known as an important drug delivery system (DDS), help to change the situation a lot. This DDS shows an outstanding active-targeting ability towards tumor cells and improves the therapeutic effect during antitumor treatment while overcoming the shortcomings mentioned above. In the following text, we will mainly focus on the various applications of rHDL in tumor targeted therapy by describing the properties, preparation, receptor active-targeting ability and antitumor effects of antineoplastic drug-loaded rHDL NPs.

Two nanoformulations induce reactive oxygen species and immunogenetic cell death for synergistic chemo-immunotherapy eradicating colorectal cancer and hepatocellular carcinoma

BACKGROUND

FOLFOX is a combinational regimen of folinic acid (FnA, FOL), fluorouracil (5-Fu, F) and oxaliplatin (OxP, OX), and has been long considered as the standard treatment of colorectal cancer (CRC) and hepatocellular carcinoma (HCC). Recent developments of nano delivery systems have provided profound promise for improving anticancer efficacy and alleviating side effects of FOLFOX. Previously, a nanoformulation (termed Nano-Folox) containing OxP derivative and FnA was developed in our laboratory using nanoprecipitation technique. Nano-Folox induced OxP-mediated immunogenic cell death (ICD)-associated antitumor immunity, which significantly suppressed tumor growth in the orthotopic CRC mouse model when administrated in combination with free 5-Fu.

METHODS

A nanoformulation (termed Nano-FdUMP) containing FdUMP (5-Fu active metabolite) was newly developed using nanoprecipitation technique and used in combination with Nano-Folox for CRC and HCC therapies.

RESULTS

Synergistic efficacy was achieved in orthotopic CRC and HCC mouse models. It resulted mainly from the fact that Nano-FdUMP mediated the formation of reactive oxygen species (ROS), which promoted the efficacy of ICD elicited by Nano-Folox. In addition, combination of Nano-Folox/Nano-FdUMP and anti-PD-L1 antibody significantly inhibited CRC liver metastasis, leading to long-term survival in mice.

CONCLUSION

This study provides proof of concept that combination of two nano delivery systems can result in successful FOLFOX-associated CRC and HCC therapies. Further optimization in terms of dosing and timing will enhance clinical potential of this combination strategy for patients.

Acyclovir in the Treatment of Herpes Viruses – A Review

Background:

Herpes Simplex (HSV) viruses are widely spread, highly contagious human pathogens. The statistics indicate that 50-90% of adults worldwide are seropositive for these viruses, mainly HSV-1 and HSV-2. The primary infection results in the appearance of watery blisters (cold sores) on the skin, lips, tongue, buccal mucosa or genitals. The ocular infection is the major cause of corneal blindness in the Western World. Once the HSV virus enters human body, it cannot be completely eradicated because HSV viruses are able to change into their latent form which can survive the treatment. The viron resides in trigeminal ganglia of the host, who becomes vulnerable to the reoccurrence of the disease during the whole lifespan. The neurotropic and neuro-invasive properties of HSV are responsible for neurodegenerative illnesses, such as Alzheimer's disease. Acyclovir and its analogues, being the inhibitors of the viral DNA replication, are the only approved medicines for HSV infection therapies.

Objective:

The current paper presents the up-to-date overview of the important pharmacological features of acyclovir, its analogues and their delivery systems including the mechanism of action, routes of administration, absorption and metabolism, as well as side effects of the therapy.

Conclusion:

Acyclovir remains the gold standard in the treatment of herpes virus infections, mainly due to the emerging of the new delivery systems improving considerably its bioavailability. The analogues of acyclovir, especially their esters, characterized by significantly higher bioavailability and safety, may gradually replace acyclovir in selected applications.

Nano Codelivery of Oxaliplatin and Folinic Acid Achieves Synergistic Chemo-Immunotherapy with 5-Fluorouracil for Colorectal Cancer and Liver Metastasis

FOLFOX, the combinational strategy of folinic acid (FnA), 5-fluorouracil (5-Fu), and oxaliplatin (OxP), has been used as standard treatment of colorectal cancer (CRC) for decades. Despite the improved survival, patients still suffer from drawbacks such as low efficacy, high toxicity, and long course of treatment. New strategies to address these issues are needed to further clinical benefits. In this study, a nanoprecipitate (C₂₆H₃₅N₉O₇Pt) was formed by the active form of OxP ([Pt(DACH)(H₂O)₂]²⁺) and FnA, which was formulated into an aminoethyl anisamide targeted PEGylated lipid nanoparticle within microemulsions using nanoprecipitation technique. The resultant formulation (namely Nano-Folox) significantly promoted the blood circulation and tumor accumulation of platinum drug and FnA in an orthotopic CRC mouse model. Emerging evidence indicates that OxP can not only provide anticancer cytotoxic effects but also induce immunogenic cell death (a type of apoptosis that primes anticancer immune responses). Consequently, Nano-Folox demonstrated favorable chemo-immunotherapeutic activities in orthotopic CRC mice. In addition, when compared to FOLFOX the significantly stronger chemo-immunotherapeutic responses were achieved by the combination of Nano-Folox and 5-Fu without showing toxicity. Moreover, the anti-PD-L1 monoclonal antibody enhanced Nano-Folox/5-Fu for decreased liver metastases in mice. These results indicate the potential of Nano-Folox-based combination strategy for the treatment of CRC.

Fabrication and Characterization of Calcium-Phosphate Lipid System for Potential Dental Application

Lipid has been widely studied as a vehicle and loading vector, but there have been no reports of any such related application in the dental field. The purpose of this research was to fabricate and characterize a nano-size calcium-phosphate lipid (CL) system as a potential vehicle in dental regeneration study, wherein the biocompatibility with dental pulp stem cells (DPSCs) was evaluated. The effect of CL on DPSCs proliferation was analyzed by a CCK-8 assay, and the anti-inflammatory effect was investigated by quantitative polymerase chain reaction (qPCR). Moreover, the effect of CL on odontogenic differentiation of inflamed DPSCs (iDPSCs) was studied by Alizarin red staining, tissue-non-specific alkaline phosphatase (TNAP) staining, qPCR, and western blot analyses. The results of this study showed that CL did not affect the proliferation of DPSCs, it down-regulated the inflammatory-associated markers (IL-1β, IL-6, TNF-α, COX-2) of DPSCs treated with Escherichia coli lipopolysaccharide (LPS), and enhanced the in-vitro odontogenic differentiation potential of iDPSCs. This novel biomaterial has a broad application prospect for its bioactivity and flexible physical property, and thus represents a promising pulpal regeneration material.

Selected nucleos(t)ide-based prescribed drugs and their multi-target activity

Nucleos(t)ide analogues play pivotal roles as antiviral, cytotoxic or immunosuppressive agents. Here, we review recent reports of nucleoside analogues that exhibit broad-spectrum activity towards multiple life-threatening RNA and DNA viruses. We also present a discussion about nucleoside antimetabolites-approved antineoplastic agents-that have recently been shown to have antiviral and/or antibacterial activity. The approved drugs and drug combinations, as well as recently identified candidates for investigation and/or experimentation, are discussed. Several examples of repurposed drugs that have already been approved for use are presented. This strategy can be crucial for the first-line treatment of acute infections or coinfections and for the management of drug-resistant strains.

Surface engineering of nanomaterials with phospholipid-polyethylene glycol-derived functional conjugates for molecular imaging and targeted therapy

In recent years, phospholipid-polyethylene glycol-derived functional conjugates have been widely employed to decorate different nanomaterials, due to their excellent biocompatibility, long blood circulation characteristics, and specific targeting capability. Numerous in vivo studies have demonstrated that nanomedicines peripherally engineered with phospholipid-polyethylene glycol-derived functional conjugates show significantly increased selective and efficient internalization by target cells/tissues. Targeting moieties including small-molecule ligands, peptides, proteins, and antibodies are generally conjugated onto PEGylated phospholipids to decorate liposomes, micelles, hybrid nanoparticles, nanocomplexes, and nanoemulsions for targeted delivery of diagnostic and therapeutic agents to diseased sites. In this review, the synthesis methods of phospholipid-polyethylene glycol-derived functional conjugates, biophysicochemical properties of nanomedicines decorated with these conjugates, factors dominating their targeting efficiency, as well as their applications for in vivo molecular imaging and targeted therapy were summarized and discussed.

Biomolecule-assisted green synthesis of nanostructured calcium phosphates and their biomedical applications

Calcium phosphates (CaPs) are ubiquitous in nature and vertebrate bones and teeth, and have high biocompatibility and promising applications in various biomedical fields. Nanostructured calcium phosphates (NCaPs) are recognized as promising nanocarriers for drug/gene/protein delivery owing to their high specific surface area, pH-responsive degradability, high drug/gene/protein loading capacity and sustained release performance. In order to control the structure and surface properties of NCaPs, various biomolecules with high biocompatibility such as nucleic acids, proteins, peptides, liposomes and phosphorus-containing biomolecules are used in the synthesis of NCaPs. Moreover, biomolecules play important roles in the synthesis processes, resulting in the formation of various NCaPs with different sizes and morphologies. At room temperature, biomolecules can play the following roles: (1) acting as a biocompatible organic phase to form biomolecule/CaP hybrid nanostructured materials; (2) serving as a biotemplate for the biomimetic mineralization of NCaPs; (3) acting as a biocompatible modifier to coat the surface of NCaPs, preventing their aggregation and increasing their colloidal stability. Under heating conditions, biomolecules can (1) control the crystallization process of NCaPs by forming biomolecule/CaP nanocomposites before heating; (2) prevent the rapid and disordered growth of NCaPs by chelating with Ca2+ ions to form precursors; (3) provide the phosphorus source for the controlled synthesis of NCaPs by using phosphorus-containing biomolecules. This review focuses on the important roles of biomolecules in the synthesis of NCaPs, which are expected to guide the design and controlled synthesis of NCaPs. Moreover, we will also summarize the biomedical applications of NCaPs in nanomedicine and tissue engineering, and discuss their current research trends and future prospects.

Gemcitabine nanoparticles promote antitumor immunity against melanoma

Myeloid-derived suppressor cells (MDSCs) promote tumor-mediated immunosuppression and cancer progression. Gemcitabine (Gem) is a MDSC-depleting chemotherapeutic agent; however, its clinical use is hampered by its drug resistance and inefficient in vivo delivery. Here we describe a strategy to formulate a Gem analogue gemcitabine monophosphate (GMP) into a lipid-coated calcium phosphate (LCP) nanoparticle, and investigate its antitumor immunity and therapeutic effects after systemic administrations. In the syngeneic mouse model of B16F10 melanoma, compared with free Gem, the LCP-formulated GMP (LCP-GMP) significantly induced apoptosis and reduced immunosuppression in the tumor microenvironment (TME). LCP-GMP effectively depleted MDSCs and regulatory T cells, and skewed macrophage polarization towards the antitumor M1 phenotype in the TME, leading to enhanced CD8⁺ T-cell immune response and profound tumor growth inhibition. Thus, engineering the in vivo delivery of MDSC-depleting agents using nanotechnology could substantially modulate immunosuppressive TME and boost T-cell immune response for enhanced antitumor efficacy.

Calcium-based biomaterials for diagnosis, treatment, and theranostics

Calcium-based (CaXs) biomaterials including calcium phosphates, calcium carbonates, calcium silicate and calcium fluoride have been widely utilized in the biomedical field owing to their excellent biocompatibility and biodegradability. In recent years, CaXs biomaterials have been strategically integrated with imaging contrast agents and therapeutic agents for various molecular imaging modalities including fluorescence imaging, magnetic resonance imaging, ultrasound imaging or multimodal imaging, as well as for various therapeutic approaches including chemotherapy, gene therapy, hyperthermia therapy, photodynamic therapy, radiation therapy, or combination therapy, even imaging-guided therapy. Compared with other inorganic biomaterials such as silica-, carbon-, and gold-based biomaterials, CaXs biomaterials can dissolve into nontoxic ions and participate in the normal metabolism of organisms. Thus, they offer safer clinical solutions for disease theranostics. This review focuses on the state-of-the-art progress in CaXs biomaterials, which covers from their categories, characteristics and preparation methods to their bioapplications including diagnosis, treatment, and theranostics. Moreover, the current trends and key problems as well as the future prospects and challenges of CaXs biomaterials are also discussed at the end.

Synthesis and cytotoxic activity of novel acyclic nucleoside analogues with functionality in click chemistry

We describe synthesis of novel acyclic nucleoside analogues which are building blocks for CuAAC reaction and their activity against two types of human cancer cell lines (HeLa, KB). Three of chosen compounds show promising cytotoxic activity. Synthesis pathway starting from simple and easily accessible substrates employing DMT or TBDPS protective groups is described. Adenosine and thymidine analogues containing alkyne moiety and adenosine analogue containing azido group were synthesized. The obtained units showed ability of forming triazole motif under the CuAAC reaction conditions.

Lipid-coated calcium phosphate nanoparticle and beyond: a versatile platform for drug delivery

In recent years, lipid-coated calcium-phosphate (LCP) nanoparticle has been developed as a versatile platform for delivery of various therapeutics including gene, protein/peptide, chemotherapeutics and theranostic agents. The high endosomal escape, coupled with the ability to efficiently encapsulate phosphorylated drugs or prodrugs, make LCP become attractive vehicle for drug delivery. Additionally, the principle behind LCP formulation has also allowed rational design of LCP-derived nanoparticles (NPs) with other solid core or lipid membrane to overcome the various drug delivery barriers. Here, we briefly review the history of the development of LCP NPs, highlight the optimisations and modulations in the development process, and summarise the major applications of LCP NPs and LCP-derived NPs in drug delivery.

Nanoformulations for combination or cascade anticancer therapy

Nanoparticle drug formulations have been extensively investigated, developed, and in some cases, approved by the Food and Drug Administration (FDA). Synergistic combinations of drugs having distinct tumor-inhibiting mechanisms and non-overlapping toxicity can circumvent the issue of treatment resistance and may be essential for effective anti-cancer therapy. At the same time, co-delivery of a combined regimen by a single nanocarrier presents a challenge due to differences in solubility, molecular weight, functional groups and encapsulation conditions between the two drugs. This review discusses cellular and microenvironment mechanisms behind treatment resistance and nanotechnology-based solutions for effective anti-cancer therapy. Co-loading or cascade delivery of multiple drugs using of polymeric nanoparticles, polymer-drug conjugates and lipid nanoparticles will be discussed along with lipid-coated drug nanoparticles developed by our lab and perspectives on combination therapy.

Quercetin Remodels the Tumor Microenvironment To Improve the Permeation, Retention, and Antitumor Effects of Nanoparticles

Our previous work demonstrated that Wnt16 expression in cisplatin-damaged tumor-associated fibroblasts is a key factor contributing to cisplatin resistance in malignancies. Natural antifibrotic compounds with low toxicities are promising candidates to downregulate Wnt16 expression, improving the antitumor effect of cisplatin nanoparticles. Upon screening several natural chemicals, we found that a dietary flavonoid, quercetin, significantly suppresses Wnt16 expression in activated fibroblasts. To facilitate drug delivery, we have prepared a targeted lipid/calcium/phosphate nanoparticle formulation consisting of a prodrug of quercetin, i.e., quercetin phosphate, with a high loading efficiency (26.6% w/w). This quercetin nanoparticle with a particle size of around 35 nm significantly improved the bioavailability and metabolic stability of the parent quercetin. Quercetin phosphate is released from the nanoparticles and converted back to the parent quercetin under physiological conditions. Following systemic administration of quercetin phosphate nanoparticles, a significant downregulation in Wnt16 expression was observed and further yielded a synergistic antitumor effect with cisplatin nanoparticles in a stroma-rich bladder carcinoma model. The α-SMA-positive fibroblast and collagen within the tumor decreased significantly after combination treatment. This suggests that the remodeling of the tumor microenvironment induced by quercetin plays a critical role in promoting the synergy. Indeed, our data further confirmed that quercetin phosphate alone significantly remodeled the tumor microenvironment and increased the penetration of second-wave nanoparticles into the tumor nests. Collectively, quercetin phosphate nanoparticles may be a safe and effective way to improve therapeutic treatment for desmoplastic tumors.

Targeting Nanocarriers with Anisamide: Fact or Artifact?

Encapsulating chemotherapeutics in nanoparticles can reduce the side effects of intravenous administration and improve their antitumor efficacy. Additionally, surface decoration of the nanocarriers with tumor-targeting ligands may enhance their specificity for cancer cells overexpressing the corresponding ligand-binding counterpart. The focus here is on anisamide, a low-molecular-weight benzamide derivative used as a tumor-directing moiety in functionalized nanosystems, based on its alleged interaction with Sigma receptors. The scintigraphic agents that initially inspired the use of anisamide for tumor targeting are described, and the published anisamide-tethered nanocarrier formulations are reviewed, together with a critical overview of the ligand's tumor-targeting properties. Moreover, anisamide's putative but dubious cellular target, the Sigma-1 receptor, is discussed with regard to its subcellular localization and implications in cancer. Data from in vivo studies reveal that the effect of anisamide on the antitumor efficacy of the decorated nanosystems varies considerably among the published reports. Together with the evidence questioning the interaction of anisamide with the Sigma receptors, the variability of anisamide's effect on the tumor deposition and the antitumor efficacy of the decorated drug carriers calls into question the extent of the ligand's tumor-targeting effect. Further research is necessary to elucidate the ligand's utility in tumor targeting.

Sigma receptor-mediated targeted delivery of anti-angiogenic multifunctional nanodrugs for combination tumor therapy

The potential of low molecular weight heparin (LMWH) in anti-angiogenic therapy has been tempered by poor in vivo delivery to the tumor cell and potentially harmful side effects, such as the risk of bleeding due to heparin's anticoagulant activity. In order to overcome these limitations and further improve the therapeutic effect of LMWH, we designed a novel combination nanosystem of LMWH and ursolic acid (UA), which is also an angiogenesis inhibitor for tumor therapy. In this system, an amphiphilic LMWH-UA (LHU) conjugate was synthesized and self-assembled into core/shell nanodrugs with combined anti-angiogenic activity and significantly reduced anticoagulant activity. Furthermore, DSPE-PEG-AA-modified LHU nanodrugs (A-LHU) were developed to facilitate the delivery of nanodrugs to the tumor. The anti-angiogenic activity of A-LHU was investigated both in vitro and in vivo. It was found that A-LHU significantly inhibited the tubular formation of human umbilical vein endothelial cells (HUVECs) (p<0.01) and the angiogenesis induced by basic fibroblast growth factor (bFGF) in a Matrigel plug assay (p<0.001). More importantly, A-LHU displayed significant inhibition on the tumor growth in B16F10-bearing mice in vivo. The level of CD31 and p-VEGFR-2 expression has demonstrated that the excellent efficacy of antitumor was associated with a decrease in angiogenesis. In conclusion, A-LHU nanodrugs are a promising multifunctional antitumor drug delivery system.

Current and Future Theranostic Applications of the Lipid-Calcium-Phosphate Nanoparticle Platform

Over the last four years, the Lipid-Calcium-Phosphate (LCP) nanoparticle platform has shown success in a wide range of treatment strategies, recently including theranostics. The high specific drug loading of radiometals into LCP, coupled with its ability to efficiently encapsulate many types of cytotoxic agents, allows a broad range of theranostic applications, many of which are yet unexplored. In addition to providing an overview of current medical imaging modalities, this review highlights the current theranostic applications for LCP using SPECT and PET, and discusses potential future uses of the platform by comparing it with both systemically and locally delivered clinical radiotherapy options as well as introducing its applications as an MRI contrast agent. Strengths and weaknesses of LCP and of nanoparticles in general are discussed, as well as caveats regarding the use of fluorescence to determine the accumulation or biodistribution of a probe.

Findings questioning the involvement of Sigma-1 receptor in the uptake of anisamide-decorated particles

Anisamide is a small benzamide previously suggested as a tumor-targeting ligand for nanocarriers and it has been shown to enhance tumor uptake in vitro as well as in vivo when grafted on the nanoparticle surface. Anisamide has been hypothesized to interact with the Sigma-1 receptor, based on the binding of larger benzamides, which contain anisamide in their structure, to this receptor. However, the interaction between anisamide and Sigma-1 receptor has never been thoroughly studied. We developed fluorescent PEGylated particles decorated with anisamide, which were preferentially taken up in vitro by melanoma cells compared to macrophages. The anisamide-decorated particles were used to study their interaction with the Sigma-1 receptor. The absence of competition of Sigma-1 receptor ligands for the particle uptake was a first indication that the receptor might not be involved in the uptake process. In addition, the extent of particle uptake did not correlate with the levels of cellular expression of Sigma-1 receptor in the cell models tested. Immunostaining of the receptor on melanoma cells revealed intracellular localization, indirectly excluding the possibility of anisamide binding to the receptor when grafted on the particles. All these data question the previously suggested Sigma-1 receptor-mediated uptake of the anisamide-decorated particles, a finding which may have an impact on the use of anisamide as a targeting ligand.

An insight into functionalized calcium based inorganic nanomaterials in biomedicine: Trends and transitions

Over the recent years the use of biocompatible and biodegradable nanoparticles in biomedicine has become a significant priority. Calcium based ceramic nanoparticles like calcium phosphate (CaP) and calcium carbonate (CaCO3) are therefore considered as attractive carriers as they are naturally present in human body with nanosize range. Their application in tissue engineering and localized controlled delivery of bioactives for bones and teeth is well established now, but recently their use has increased significantly as carrier of bioactives through other routes also. These delivery systems have become most potential alternatives to other commonly used delivery system because of their cost effectiveness, biodegradability, chemical stability, controlled and stimuli responsive behaviour. This review comprehensively covers their characteristic features, method of preparation and applications but the thrust is to focus their recent development, functionalization and use in systemic delivery. On the same platform mineralization of other nanoparticulate delivery system which has widened their application drug delivery will be discussed. The emphasis has been given on their pH dependent properties which make them excellent carriers for tumour targeting and intracellular delivery. Finally this review also attempts to discuss their drawback which limits their clinical utility.

NCI investment in nanotechnology: achievements and challenges for the future

Nanotechnology offers an exceptional and unique opportunity for developing a new generation of tools addressing persistent challenges to progress in cancer research and clinical care. The National Cancer Institute (NCI) recognizes this potential, which is why it invests roughly $150 M per year in nanobiotechnology training, research and development. By exploiting the various capacities of nanomaterials, the range of nanoscale vectors and probes potentially available suggests much is possible for precisely investigating, manipulating, and targeting the mechanisms of cancer across the full spectrum of research and clinical care. NCI has played a key role among federal R&D agencies in recognizing early the value of nanobiotechnology in medicine and committing to its development as well as providing training support for new investigators in the field. These investments have allowed many in the research community to pursue breakthrough capabilities that have already yielded broad benefits. Presented here is an overview of how NCI has made these investments with some consideration of how it will continue to work with this research community to pursue paradigm-changing innovations that offer relief from the burdens of cancer.