Novel and simple loading procedure of cisplatin into liposomes and targeting tumor endothelial cells

Exploration of sialic acid receptors as a potential target for cancer treatment: A comprehensive review

The potential to target anticancer drugs directly to cancer cells is the most difficult challenge in the current scenario. Progressive works are being done on multifarious receptors and are on the horizon, expected to facilitate tailored treatment for cancer. Among several receptors, one is the sialic acid (SA) receptor by which cancer cells can be targeted directly as hyper sialylation is one of the most distinguishing characteristics of cancer cells. SA receptors have shown tremendous potential for tumor targeting because of their elevated expression in a range of human malignancies including prostate, breast, gastric cells, myeloid leukemia, liver, etc. This article reviews the overexpression of SA receptors in various tumors and diverse strategies for targeting these receptors to deliver drugs, enzymes, and genes for therapeutic applications. It also summarizes the diagnostic applications of SA-grafted nanoparticles for imaging various SA-overexpressing cancer cells and technological advances that are propelling sialic acid to the forefront of cancer therapy.

Endothelial Cell Adhesion Molecules- (un)Attainable Targets for Nanomedicines

Endothelial cell adhesion molecules have long been proposed as promising targets in many pathologies. Despite promising preclinical data, several efforts to develop small molecule inhibitors or monoclonal antibodies (mAbs) against cell adhesion molecules (CAMs) ended in clinical-stage failure. In parallel, many well-validated approaches for targeting CAMs with nanomedicine (NM) were reported over the years. A wide range of potential applications has been demonstrated in various preclinical studies, from drug delivery to the tumor vasculature, imaging of the inflamed endothelium, or blocking immune cells infiltration. However, no NM drug candidate emerged further into clinical development. In this review, we will summarize the most advanced examples of CAM-targeted NMs and juxtapose them with known traditional drugs against CAMs, in an attempt to identify important translational hurdles. Most importantly, we will summarize the proposed strategies to enhance endothelial CAM targeting by NMs, in an attempt to offer a catalog of tools for further development.

Liposomes Co-Encapsulating Cisplatin/Mifepristone Improve the Effect on Cervical Cancer: In Vitro and In Vivo Assessment

Cervical cancer is usually diagnosed in the later stages despite many campaigns for early detection and continues to be a major public health problem. The standard treatment is cisplatin-based chemotherapy plus radiotherapy, but patient response is far from ideal. In the research for new drugs that enhance the activity of cisplatin, different therapeutic agents have been tested, among them the antiprogestin mifepristone. Nevertheless, the efficacy of cisplatin is limited by its low specificity for tumor tissue, which causes severe side effects. Additionally, cervical tumors often become drug resistant. These problems could possibly be addressed by the use of liposome nanoparticles to encapsulate drugs and deliver them to the target. The aim of this study was to prepare liposome nanoparticles that co-encapsulate cisplatin and mifepristone, evaluate their cytotoxicity against HeLa cells and in vivo with subcutaneous inoculations of xenografts in nu/nu mice, and examine some plausible mechanisms of action. The liposomes were elaborated by the reverse-phase method and characterized by physicochemical tests. The nanoparticles had a mean particle size of 109 ± 5.4 nm and a Zeta potential of -38.7 ± 1.2 mV, the latter parameter indicating a stable formulation. These drug-loaded liposomes significantly decreased cell viability in vitro and tumor size in vivo, without generating systemic toxicity in the animals. There was evidence of cell cycle arrest and increased apoptosis. The promising results with the co-encapsulation of cisplatin/mifepristone warrant further research.

Dual-Ligand Modification of PEGylated Liposomes Used for Targeted Doxorubicin Delivery to Enhance Anticancer Efficacy

Mannose receptor (CD206) and E-selectin are selectively expressed in M2-like tumor-associated macrophages (M2-TAMs) and activated endothelial cells of vessels surrounding tumor tissues. With the knowledge that D-mannose is the natural ligand of mannose receptors and L-fucose is the key calcium chelator for tumor-associated carbohydrate antigens (TACAs) binding to E-selectin, herein, we firstly reported D-mannose polyethylene glycol (PEG) conjugates (Man-PEG) and L-fucose PEG conjugates (Fuc-PEG) co-modified liposomal doxorubicin (DOX-MFPL) to improve tumor-targeting ability. The dual-ligand modified PEGylated liposomes (DOX-MFPL) were assessed by both in vitro and in vivo trials. Compared with the single-ligand D-mannose- or L-fucose-modified liposomes (DOX-MPL or DOX-FPL), DOX-MFPL achieved an increased distribution of DOX in tumor tissues. The antitumor study based on S180 tumor-bearing mice was conducted and the superior tumor inhibitory rate was shown with DOX-MFPL, probably owing to the superior tumor-targeting effect of DOX-MFPL and the modulation of the tumor microenvironment with the exhaustion of TAMs. In general, the dual-ligand drug delivery systems are expected to be promising in the development of specific and efficient methods for tumor treatment.

Anticancer Effect of Cisplatin-Loaded Poly (Butylcyanoacrylate) Nanoparticles on A172 Brain Cancer Cells Line

Background: Drug delivery systems have been designed to achieve targeted delivery and control the release rate of the drugs. A serious challenge associated with drug delivery systems is the presence of the blood-brain barrier which limits drugs penetration. In the current study, the effects of cisplatin nanoparticles on A172 brain cancer cell line were investigated. Methods: Cisplatin nanoparticles were produced by miniemulsion polymerization technique and their properties were evaluated. Drug release assay was performed to characterize the nanoparticles’ properties. Here, we examined the effects of cisplatin nanoparticles and free form of cisplatin on A172 cancer cell line. MTT assay was performed for different concentrations of the drug. To measure the apoptosis rate in A172 cell line in the presence of cisplatin nanoparticles or its free from, Annexin V staining method was used. Results: Our results indicated that loading type of cisplatin was physical loading and only 4.7% of cisplatin was released after 68 h. Furthermore, MTT assay showed that cisplatin nanoparticles in all concentrations had more cytotoxic effects on the cells comparing with the free form of cisplatin and control groups. We also showed that cisplatin nanoparticles could increase apoptosis in cancer cells more than the drug in the free form by using flow cytometry technique. Conclusion: Overall, these findings proved that cisplatin loaded on poly (Butylcyanoacrylate) nanoparticles, was more efficient than the free form of cisplatin in treating A172 cancer cell line.

Sialyl LewisX mimic-decorated liposomes for anti-angiogenic everolimus delivery to E-selectin expressing endothelial cells

In this study, we developed novel E-selectin-targeting liposomes, i.e., 3′-(1-carboxy)ethyl sialyl LewisX (3′-CE sLeX) mimic liposomes, for targeted delivery of everolimus (EVE) in anti-angiogenic therapy. We investigated the uptake and efficacy of these E-selectin targeting liposomes in inflammatory cytokine-treated human umbilical vein endothelial cells (HUVECs). The uptake of EVE in 3′-CE sLeX mimic liposomes increased steadily and almost caught up with the uptake of plain EVE at 3 h, which was higher than that in PEGylated liposomes (PEG-liposomes). Inhibition of uptake by anti-E-selectin antibody suggested involvement of E-selectin-mediated endocytotic processes. Migration in cells treated with EVE/3′-CE sLeX mimic liposomes was suppressed by more than half when compared to the control. This treatment was also seen to significantly inhibit the formation of capillary tubes and networks. In addition, Thr389 phosphorylation of pS6 kinase, as a marker of mTOR activity, was remarkably suppressed to less than endogenous levels by EVE/3′-CE sLeX mimic liposomes. In conclusion, the present study demonstrated that EVE/3′-CE sLeX mimic liposomes were intracellularly taken up by E-selectin and prompted anti-angiogenic effects of EVE involved in the mTOR signaling pathway. However, moderate retention of EVE in the liposomes might limit the targeting ability of 3′-CE sLeX mimic liposomes.

Novel E-selectin-targeting liposomes deliver everolimus to E-selectin expressing endothelial cells and accelerate its anti-angiogenic effect.

Liposomes Loaded with Cisplatin and Magnetic Nanoparticles: Physicochemical Characterization, Pharmacokinetics, and In-Vitro Efficacy

With the aim improving drug delivery, liposomes have been employed as carriers for chemotherapeutics achieving promising results; their co-encapsulation with magnetic nanoparticles is evaluated in this work. The objective of this study was to examine the physicochemical characteristics, the pharmacokinetic behaviour, and the efficacy of pegylated liposomes loaded with cisplatin and magnetic nanoparticles (magnetite) (Cis-MLs). Cis-MLs were prepared by a modified reverse-phase evaporation method. To characterize their physicochemical properties, an evaluation was made of particle size, ζ-potential, phospholipid and cholesterol concentration, phase transition temperature (T_m), the encapsulation efficiency of cisplatin and magnetite, and drug release profiles. Additionally, pharmacokinetic studies were conducted on normal Wistar rats, while apoptosis and the cytotoxic effect were assessed with HeLa cells. We present a method for simultaneously encapsulating cisplatin at the core and also embedding magnetite nanoparticles on the membrane of liposomes with a mean vesicular size of 104.4 ± 11.5 nm and a ζ-potential of −40.5 ± 0.8 mV, affording a stable formulation with a safe pharmacokinetic profile. These liposomes elicited a significant effect on cell viability and triggered apoptosis in HeLa cells.

Practical Liposomal Formulation for Taxanes with Polyethoxylated Castor Oil and Ethanol with Complete Encapsulation Efficiency and High Loading Efficiency

Taxanes including paclitaxel and docetaxel are effective anticancer agents preferably sufficient for liposomal drug delivery. However, the encapsulation of these drugs with effective amounts into conventional liposomes is difficult due to their high hydrophobicity. Therefore, an effective encapsulation strategy for liposomal taxanes has been eagerly anticipated. In this study, the mixture of polyethoxylated castor oil (Cremophor EL) and ethanol containing phosphate buffered saline termed as CEP was employed as a solvent of the inner hydrophilic core of liposomes where taxanes should be incorporated. Docetaxel-, paclitaxel-, or 7-oxacetylglycosylated paclitaxel-encapsulating liposomes were successfully prepared with almost 100% of encapsulation efficiency and 29.9, 15.4, or 29.1 mol% of loading efficiency, respectively. We then applied the docetaxel-encapsulating liposomes for targeted drug delivery. Docetaxel-encapsulating liposomes were successfully developed HER2-targeted drug delivery by coupling HER2-specific binding peptide on liposome surface. The HER2-targeting liposomes exhibited HER2-specific internalization and enhanced anticancer activity in vitro. Therefore, we propose the sophisticated preparation of liposomal taxanes using CEP as a promising formulation for effective cancer therapies.

Preclinical evaluation of cisplatin-incorporated bio-nanocapsules as chemo-radiotherapy for human hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) has continued to increase worldwide, and advanced HCC is difficult to treat using the currently available therapeutics. Chemoradiotherapy with cisplatin (cis-diamminedichloroplatinum, CDDP) is expected to confer a curative benefit on HCC patients; however, its application is limited due to side-effects such as acute nephrotoxicity as well as the conventionally limited application of chemoradiotherapy for HCC. For the practical application of this drug in the clinical setting, we formulated a novel drug carrier-comprising bio-nanocapsule (BNC) and liposomal CDDP (BNC-LP-CDDP) that recognizes the human liver and releases CDDP. BNC-LP-CDDP showed selectively high cytotoxicity for HCC cells, and markedly reduced the survival fractions of HCC when combined with ionizing radiation (IR) treatment in in vitro assays. In particular, the treatment of mice bearing human HCC with BNC-LP-CDDP and 3 Gy IR showed 95.68% growth inhibition, whereas IR treatment alone showed 65.6% growth inhibition. Moreover, BNC-LP-CDDP led to the withdrawal of CDDP-induced nephrotoxicity. These results indicate that BNC-LP-CDDP in combination with IR markedly enhanced the chemo-radiotherapeutic efficacy and eliminated CDDP induced nephrotoxicity, thus, suggesting the potential for its clinical application as human HCC therapy.

Encapsulation, controlled release, and antitumor efficacy of cisplatin delivered in liposomes composed of sterol-modified phospholipids

We employed a recently introduced class of sterol-modified lipids (SML) to produce m-PEG-DSPE containing liposome compositions with a range of cis-platinum content release rates. SML have a cholesterol succinate attached to the phosphatidylglycerol head group and a fatty acid at the 2 position. These compositions were compared to the well-studied liposome phospholipid compositions: mPEG-DSPE/Hydrogenated Soy PC/cholesterol or mPEG-DSPE/POPC/cholesterol to determine the effect of the cis-platinum release extent on C26 tumor proliferation in the BALB/c colon carcinoma mouse model. The release rates of cis-platinum from liposomes composed of SML are a function of the acyl chain length. SML-liposomes with shorter acyl chain lengths C-8 provided more rapid cisplatin release, lower in vitro IC50, and were easier to formulate compared to liposomes using traditional phospholipid compositions. Similar to other liposome cis-platinum formulations, the half-life of m-PEG-DSPE SML liposome cisplatin is substantially longer than the free drug. This resulted in a higher tumor cisplatin concentration at 48h post-dosing compared to the free drug and higher Pt-DNA adducts in the tumor. Moreover, the maximum tolerated dose of the liposome formulations where up to four fold greater than the free drug. Using X-ray fluorescence spectroscopy on tumor sections, we compared the location of platinum, to the location of a fluorescence lipid incorporated in the liposomes. The liposome platinum co-localized with the fluorescent lipid and both were non-uniformly distributed in the tumor. Non-encapsulated Cis-platinum, albeit at a low concentration, was more uniformly distributed thorough the tumor. Three liposome formulations, including the well-studied hydrogenated HSPC composition, had better antitumor activity in the murine colon 26 carcinoma model as compared to the free drug at the same dose but the SML liposome platinum formulations did not perform better than the HSPC formulation.

Nanoparticle formulations of cisplatin for cancer therapy

The genotoxic agent cisplatin, used alone or in combination with radiation and/or other chemotherapeutic agents, is an important first-line chemotherapy for a broad range of cancers. The clinical utility of cisplatin is limited both by intrinsic and acquired resistance and dose-limiting normal tissue toxicity. That cisplatin shows little selectivity for tumor versus normal tissue may be a critical factor limiting its value. To overcome the low therapeutic ratio of the free drug, macromolecular, liposomal, and nanoparticle drug delivery systems have been explored toward leveraging the enhanced permeability and retention effect and promoting delivery of cisplatin to tumors. Here, we survey recent advances in nanoparticle formulations of cisplatin, focusing on agents that show promise in preclinical or clinical settings. WIREs Nanomed Nanobiotechnol 2016, 8:776-791. doi: 10.1002/wnan.1390 For further resources related to this article, please visit the WIREs website.

Preparation, characterization, and cytotoxic effects of liposomal nanoparticles containing cisplatin: an in vitro study

Cisplatin is a chemotherapeutic agent used for treating various malignancies. The study aimed to prepare pegylated liposomal cisplatin and evaluate its efficacy against human breast cancer cell line MCF-7. Drug-loaded nanoparticles were synthesized by reverse phase evaporation technique. The study is highlighted by extensive characterization of nanoparticles in terms of nanoparticle morphology, type of drug entrapment, cisplatin retention capability, and cytotoxicity effects. The size, size distribution, and zeta potential of nanodrug were estimated 142 nm, 0.33, and -22 mV, respectively. Drug-loading efficiency was equal to 48% that occurred physically. Furthermore, high retention capability (39% of drug was released after 72 h) with significantly enhanced cytotoxicity of nanodrug (1.75 times more than the standard drug) confirmed the potency of liposomal nanoparticles as proper cisplatin carrier.

Characterization and in vitro evaluation of nimotuzumab conjugated with cisplatin-loaded liposomes

In this paper, we report the conjugation of the humanized monoclonal antibody nimotuzumab with cisplatin-loaded liposomes and the in vitro evaluation of its affinity for tumor cells. The conjugation procedure was performed through derivatization of nimotuzumab with N-succinimidyl S-acetylthioacetate (SATA) followed by a covalent attachment with maleimide groups at the end of PEG-DSPE chains located at the membrane of pre-formed liposomes. Confocal microscopy was performed to evaluate the immunoliposome affinity for EGFR antigens from human epidermoid carcinoma (A-431) and normal lung (MRC-5) cell lines. Results showed that the procedures implemented in this work do not affect the capability of the nimotuzumab-immunoliposomes to recognize the tumor cells, which overexpress the EGFR antigens.

Determination of Liposomal Cisplatin by High-Performance Liquid Chromatography and Its Application in Pharmacokinetic Studies

Liposomes have been employed as carriers for antineoplastic drugs to improve delivery. We describe an HPLC-UV method for determining cisplatin levels in liposomal and biological samples, which represents an attractive alternative to the widely used flame atomic absorption spectroscopy. Liposomal cisplatin was extracted from liposomes, plasma and tissue samples by using acetonitrile and separated on a Symmetry C18 column. The mobile phase was a mixture of water, methanol and acetonitrile, and detection was performed at 254 nm. The method was linear in the range of 0.5-10 µg/mL. Using this method, cisplatin concentration was measured in plasma, kidney, liver and tumor at different times post-administration of liposomal cisplatin. This method is proved suitable for measuring the levels of cisplatin encapsulated in a liposomal system, in plasma or tissue samples of experimental animals, after intravenous administration of liposomal cisplatin. Owing to the small plasma volume employed, a complete pharmacokinetic study can be done with a single animal.

Tunable Biodegradable Nanocomposite Hydrogel for Improved Cisplatin Efficacy on HCT-116 Colorectal Cancer Cells and Decreased Toxicity in Rats

This work describes the development of a modified nanocomposite thermosensitive hydrogel for controlled cisplatin release and improved cytotoxicity with decreased side effects. The system was characterized in terms of physical properties, morphological architecture and in vitro cisplatin release. Cytotoxicity was tested against human colorectal carcinoma HCT-116. In vivo studies were conducted to evaluate the acute toxicity in terms of rats' survival rate and body weight loss. Nephro and hepatotoxicities were evaluated followed by histopathological alterations of various tissue organs. Nanocomposite thermosensitive hydrogel containing nanosized carrier conferred density and stiffness allowing a zero order drug release for 14 days. Enhanced cytotoxicity with 2-fold decrease in cisplatin IC50 was accomplished. A linear in vivo-in vitro correlation was proved for the system degradation. Higher animal survival rate and lower tissue toxicities proved the decreased toxicity of cisplatin nanocomposite compared to its solution.

Release of siRNA from Liposomes Induced by Curcumin

Liposomes are a potential carrier of small interfering RNA (siRNA) for drug delivery systems (DDS). In this study, we searched for a molecule capable of controlling the release of siRNA from a certain type of liposomes and found that curcumin could induce the release of siRNA from the liposomes encapsulating siRNA within 30 min. However, the release of siRNA from the liposomes by curcumin showed a unique dose-response (i.e., bell-shaped curve) with a maximal induction at around 60 μg/ml of curcumin. Liposomal lipid compositions and temperatures influenced the efficiency in the release of siRNA induced by curcumin. About 10% of curcumin at a 60 μg/ml dose was incorporated into the liposomes within 30 min under our experimental conditions. Our results suggest a possibility that curcumin is useful in controlling the permeability of liposomes carrying large molecules like siRNA.

pH sensitive polymeric complex of cisplatin with hyaluronic acid exhibits tumor-targeted delivery and improved in vivo antitumor effect

Cisplatin (CDDP) is widely used anticancer drug for various solid tumors including lung cancer. However, its indiscriminate distribution causes serious adverse effects and limits its therapeutic effect. In this study, by using hyaluronic acid (HA) we synthesized a complex of CDDP (HA-CDDP), by utilizing ionic interaction between Pt(2+) of CDDP with carboxyl group of HA. The mean HA-CDDP particle size was 208.5nm in PBS according to dynamic light scattering which was also confirmed by TEM, which could exert tumor-targeting property by enhanced permeability and retention (EPR) effect. The CDDP loading in this preparation was 13% (w/w), and release rate of free CDDP from the HA-CDDP complex at physiological pH (7.4) was ∼20%/day. However, in acidic pH the release was much faster, i.e., ∼95% of CDDP was released in 72h at pH 5.5. Moreover, HA-CDDP showed a 2.5-fold higher tumor accumulation than free CDDP whereas no increase of distribution was found in most normal tissues. In addition, because HA receptor CD44 is overexpressed in many tumor cells, we also observed CD44-based endocytosis of HA-CDDP in mouse lung carcinoma LCC cells. These findings together suggest that HA-CDDP may show tumor-selective cytotoxicity by taking advantage of EPR effect, weak acidic environment of tumor tissues (e.g., pH 6∼7), as well as CD44-based intracellular uptake. As expected, HA-CDDP exhibited much improved therapeutic effect than free CDDP in mouse LCC tumor model, whereas no apparent side effect was found. These findings may shed some light on the potential utility of HA for development of tumor-targeted polymeric CDDP drugs, which need further investigations.

Nanobiotechnology for the Therapeutic Targeting of Cancer Cells in Blood

During metastasis, circulating tumor cells migrate away from a primary tumor via the blood circulation to form secondary tumors in distant organs. Mounting evidence from clinical observations indicates that the number of circulating tumor cells (CTCs) in the blood correlates with the progression of solid tumors before and during chemotherapy. Beyond the well-established role of CTCs as a fluid biopsy, however, the field of targeting CTCs for the prevention or reduction of metastases has just emerged. Conventional cancer therapeutics have a relatively short circulation time in the blood which may render the killing of CTCs inefficient due to reduced exposure of CTCs to drugs. Nevertheless, over the past few decades, the development of nanoparticles and nanoformulations to improve the half-life and release profile of drugs in circulation has rejuvenated certain traditional medicines in the emerging field of CTC neutralization. This review focuses on how the principles of nanomedicine may be applied to target CTCs. Moreover, inspired by the interactions between CTCs and host cells in the blood circulation, novel biomimetic approaches for targeted drug delivery are presented.

Cisplatin-alginate conjugate liposomes for targeted delivery to EGFR-positive ovarian cancer cells

Systemic side effects and low aqueous solubility have limited the clinical use of cisplatin (CDDP) in ovarian carcinoma and have contributed to failures in developing effective drug delivery systems. In order to develop a novel drug delivery system with enhanced efficacy and minimal adverse effects, we exploited the properties of sodium alginate (SA) to synthesize CDDP-SA conjugate (CS), which is highly soluble and readily incorporated into liposomes (CS-PEG-Lip). Epidermal growth factor receptor (EGFR) is overexpressed in many ovarian cancers, therefore we modified EGF on the liposomes (CS-EGF-Lip) to specifically target EGFR-expressing tumors, thereby increasing the bioavailability and efficacy of CDDP. In vitro experiments confirmed that EGF-Lip selectively recognized EGFR-positive SKOV3 cells and effectively penetrated tumor spheroids. We demonstrated that CS-EGF-Lip possessed satisfactory size distribution and exhibited significantly improved encapsulation and loading efficiency. Furthermore, CS-EGF-Lip sustained release of CDDP in vitro, suggesting that CS-EGF-Lip may retain the antitumor activity of CDDP. Inhibition of proliferation and migration was also greater with CS-EGF-Lip compared to CDDP. In vivo xenograft experiments revealed that administration of CS-EGF-Lip enhanced delivery of CDDP into ovarian tumor tissues and improved the antitumor efficacy of CDDP, while reducing nephrotoxicity and body weight loss in mice. These results suggest that CS-EGF-Lip may offer a promising strategy for CDDP delivery in the treatment of EGFR-positive ovarian carcinoma or similar tumors, with enhanced efficacy and fewer adverse effects.

Targeting liposomes loaded with melphalan prodrug to tumour vasculature via the Sialyl Lewis X selectin ligand

Earlier we showed that liposome formulation of DL-melphalan lipophilic prodrug bearing tetrasaccharide Sialyl Lewis X (SiaLe^X) caused prolonged therapeutic effect on mammary cancer in mice. Here, we compare antivascular effect of SiaLe^X-liposomes loaded with diglyceride ester of melphalan (Mlph) against SiaLe^X-free formulation in Lewis lung carcinoma model.

METHODS

Liposomes of egg phosphatidylcholine/yeast phosphatidylinositol/1,2-dioleoyl glycerol (DOG) conjugate of Mlph/±SiaLe^X-PEG_8-15-DOG, 8:1:1:0.2 by mol, were prepared by standard extrusion. After two intravenous injections with Mlph or liposomes under either standard or delayed treatment protocols, vascular-disrupting effects of the preparations were evaluated basing on tumour section histomorphology, lectin perfusion assay and immunohistochemistry (anti-CD31 staining) data. Also, untreated mice were administered with fluorescently-labelled liposomes to assess their distribution in tumour sections with confocal laser scanning microscopy.

RESULTS

Two injections of SiaLe^X-liposomes reproducibly caused severe injuries of tumour vessels. SiaLe^X-liposomes co-localized with CD31 marker on vascular endothelium while the non-targeted formulation extravasated into tumour.

DISCUSSION

Cytotoxic SiaLe^X-liposomes exhibit superior vascular-disrupting properties compared to non-targeted liposomes, yet the effect starts to transform into gain in tumour growth inhibition only under delayed treatment regimen.

CONCLUSION

SiaLe^X-ligand provides targeting of cytotoxic liposomes to tumour endothelium and subsequent antivascular effect.

A novel drug delivery system of intraperitoneal chemotherapy for peritoneal carcinomatosis using gelatin microspheres incorporating cisplatin

BACKGROUND

Peritoneal carcinomatosis is a poor prognostic factor for patients with gastrointestinal, gynecologic, and pancreatic cancer. Cisplatin (CDDP) is among the most effective anti-cancer agents, although its adverse effects remain unresolved. For the treatment of peritoneal carcinomatosis with high-dose CDDP, it is necessary to design a new delivery system of CDDP that can decrease systemic toxicity and achieve a better targeted, high-dose chemotherapy.

METHODS

Microspheres were prepared from gelatin of a nontoxic, biodegradable material for the sustained release of CDDP. The gelatin microspheres incorporating CDDP (GM-CDDP) were injected intraperitoneally into a mouse model of peritoneal carcinomatosis; their therapeutic efficacy and adverse effects were evaluated in comparison with intraperitoneal administration of free CDDP.

RESULTS

GM-CDDP released CDDP in the peritoneal cavity as a result of gelatin biodegradation. Mice treated with microspheres in the peritoneal cavity lived longer than mice treated with free CDDP (74 ± 23 vs 40 ± 23 days; P < .05). The mice treated with GM-CDDP also lost no weight, whereas the free CDDP group lost approximately 20% body weight (106 ± 5% vs 80 ± 7%; P < .001; body weight on day 1 = 100%). GM-CDDP significantly decreased the nephrotoxicity and hematotoxicity of CDDP.

CONCLUSION

GM decreased the adverse effects of CDDP and allowed high-dose intraperitoneal chemotherapy with the control of CDDP. This technique of gradual local release may allow us to provide a high-dose, targeted, intraperitoneal chemotherapy with CDDP, resulting in enhanced anti-cancer effects. These gelatin microspheres may be useful as a drug carrier for the treatment of peritoneal carcinomatosis.

Polybutylcyanoacrylate nanoparticles and drugs of the platinum family: last status

Cisplatinum and carboplatinum drugs from platinum-containing family are anti-cancer drugs. Using these drugs causes side effects. Targeted and selective prescription decreases side effects of the drugs. This can be achieved using nanotechnology. In this study, cisplatinum and carboplatinum drugs were loaded on polybutylcyanoacrylate nanoparticles using emulsion polymerization method. To determine amount of loaded drug onto nanoparticle, spectrophotometry method was used. Evaluation of cytotoxicity of such nanoparticles was performed on MCF-7 cell line using MTT assay. Loading percentage of cisplatinum and carboplatinum drugs on nanoparticles were estimated 4 and 6 %, respectively. Cytotoxicity survival rate for cisplatinum and nanoparticle containing cisplatinum at the lowest concentration (p < 0.01) (20 μM) were estimated 64 ± 1 and 67 ± 0.5 %, respectively. These values at the highest concentration (p < 0.01) (160 μM) were measured 28 ± 0.7 and 31 ± 0.4 %. Additionally for carboplatinum and nanoparticles containing carboplatinum at the concentration (p < 0.01) (20 μM) amounts were estimated to be 80 ± 0.6 and 84 ± 0.6 %, while at the concentration (p < 0.01) (160 μM) were identified to be 44 ± 0.5 and 51 ± 0.2 %, respectively. Probably, due to low level of loading, cytotoxicity of both drugs at nano particle status was decreased in comparison with their standard form.

Shell crosslinked knedel-like nanoparticles for delivery of cisplatin: effects of crosslinking

Polymeric micelles and shell crosslinked knedel-like (SCK) nanoparticles were loaded with up to 48% (w/w) cisplatin. These spherical cisplatin-loaded nanoparticles displayed sustained platinum release over 5 days in PBS, enhanced stability over free cisplatin in aqueous milieu, and significant antitumor activity in vitro against two cancer cell lines.

E-selectin as a target for drug delivery and molecular imaging

E-selectin, also known as CD62E, is a cell adhesion molecule expressed on endothelial cells activated by cytokines. Like other selectins, it plays an important part in inflammation and in the adhesion of metastatic cancer cells to the endothelium. E-selectin recognizes and binds to sialylated carbohydrates present on the surface proteins of certain leukocytes. E-selectin has been chosen as a target for several therapeutic and medical imaging applications, based on its expression in the vicinity of inflammation, infection or cancer. These systems for drug delivery and molecular imaging include immunoconjugates, liposomes, nanoparticles, and microparticles prepared from a wide range of starting materials including lipids, synthetic polymers, polypeptides and organo-metallic structures. After a brief introduction presenting the selectin family and their implication in physiology and pathology, this review focuses on the formulation of these new delivery systems targeting E-selectin at a molecular level.

Developing a highly stable PLGA-mPEG nanoparticle loaded with cisplatin for chemotherapy of ovarian cancer

Background

Cisplatin is a potent anticancer drug, but its clinical application has been limited due to its undesirable physicochemical characteristics and severe side effects. Better drug formulations for cisplatin are highly desired.

Methodology/Principal Findings

Herein, we have developed a nanoparticle formulation for cisplatin with high encapsulation efficiency and reduced toxicity by using cisplatin-crosslinked carboxymethyl cellulose (CMC) core nanoparticles made from poly(lactide-co-glycolide)-monomethoxy-poly(polyethylene glycol) copolymers (PLGA-mPEG). The nanoparticles have an average diameter of approximately 80 nm measured by transmission electron microscope (TEM). The encapsulation efficiency of cisplatin in the nanoparticles is up to 72%. Meanwhile, we have also observed a controlled release of cisplatin in a sustained manner and dose-dependent treatment efficacy of cisplatin-loaded nanoparticles against IGROV1-CP cells. Moreover, the median lethal dose (LD₅₀) of the cisplatin-loaded nanoparticles was more than 100 mg/kg by intravenous administration, which was much higher than that of free cisplatin.

Conclusion

This developed cisplatin-loaded nanoparticle is a promising formulation for the delivery of cisplatin, which will be an effective therapeutic regimen of ovarian cancer without severe side effects and cumulative toxicity.

Sialic acid as a potential approach for the protection and targeting of nanocarriers

INTRODUCTION

Nanocarriers are considered to be one of the most innovative drug delivery systems, owing to their high potential in drug protection, delivery and targeting to the diseased site. Unfortunately, their applicability is hampered mainly by their uptake, due to macrophagic recognition and lack of specificity, if not properly engineered.

AREAS COVERED

Sialic acid (SA) and its derivatives have recently been studied in order to govern their stealthness as carriers and their effectiveness as targeting moieties. In this review, the most outstanding research (in vitro and in vivo) dealing with the use of SA or its derivatives to modify the surface carriers, in order to achieve targeted or stealth nanosystems, is summarized. Moreover, the application of SA or its derivatives as modifiers in cancer targeting and therapy, and in recognition purposes, is considered.

EXPERT OPINION

The application of SA-based strategies for nanocarrier engineering represents one of the most stimulating challenges in drug delivery and drug targeting. Both in vivo and in vitro results on stealth or targeted nanocarriers, modified with different kinds of SA or SA derivative, have highlighted the great potential of this approach. These studies have drawn attention to both the advantages (stealth properties, targeting ability, cancer inhibition, viral and inflammation recognition, brain targeting) and the possible disadvantages (i.e., presence of possible multi-target side effect outputs) of this strategy, and overall suggests that further investigations on this strategy are required.

A cast-mold approach to iron oxide and Pt/iron oxide nanocontainers and nanoparticles with a reactive concave surface

We report the synthesis of various iron oxide nanocontainers and Pt-iron oxide nanoparticles based on a cast-mold approach, starting from nanoparticles having a metal core (either Au or AuPt) and an iron oxide shell. Upon annealing, the particles evolve to asymmetric core-shells and then to heterodimers. If iodine is used to leach Au out of these structures, asymmetric core-shells evolve into "nanocontainers", that is, iron oxide nanoparticles enclosing a cavity accessible through nanometer-sized pores, while heterodimers evolve into particles with a concave region. When starting from a metal domain made of AuPt, selective leaching of the Au atoms yields the same iron oxide nanoparticle morphologies but now encasing Pt domains (in their concave region or in their cavity). We found that the concave nanoparticles are capable of destabilizing Au nanocrystals of sizes matching that of the concave region. In addition, for the nanocontainers, we propose two different applications: (i) we demonstrate loading of the cavity region of the nanocontainers with the antitumoral drug cis-platin; and (ii) we show that nanocontainers encasing Pt domains can act as recoverable photocatalysts for the reduction of a model dye.