A unique squalenoylated and nonpegylated doxorubicin nanomedicine with systemic long-circulating properties and anticancer activity.

We identified that the chemical linkage of the anticancer drug doxorubicin onto squalene, a natural lipid precursor of the cholesterol's biosynthesis, led to the formation of squalenoyl doxorubicin (SQ-Dox) nanoassemblies of 130-nm mean diameter, with an original "loop-train" structure. This unique nanomedicine demonstrates: (i) high drug payload, (ii) decreased toxicity of the coupled anticancer compound, (iii) improved therapeutic response, (iv) use of biocompatible transporter material, and (v) ease of preparation, all criteria that are not combined in the currently available nanodrugs. Cell culture viability tests and apoptosis assays showed that SQ-Dox nanoassemblies displayed comparable antiproliferative and cytotoxic effects than the native doxorubicin because of the high activity of apoptotic mediators, such as caspase-3 and poly(ADP-ribose) polymerase. In vivo experiments have shown that the SQ-Dox nanomedicine dramatically improved the anticancer efficacy, compared with free doxorubicin. Particularly, the M109 lung tumors that did not respond to doxorubicin treatment were found inhibited by 90% when treated with SQ-Dox nanoassemblies. SQ-Dox nanoassembly-treated MiaPaCa-2 pancreatic tumor xenografts in mice decreased by 95% compared with the tumors in the saline-treated mice, which was significantly higher than the 29% reduction achieved by native doxorubicin. Concerning toxicity, SQ-Dox nanoassemblies showed a fivefold higher maximum-tolerated dose than the free drug, and moreover, the cardiotoxicity study has evidenced that SQ-Dox nanoassemblies did not cause any myocardial lesions, such as those induced by the free doxorubicin treatment. Taken together, these findings demonstrate that SQ-Dox nanoassemblies make tumor cells more sensitive to doxorubicin and reduce the cardiac toxicity, thus providing a remarkable improvement in the drug's therapeutic index.

Nanotechnology for therapy and imaging of liver diseases.

Nanotechnology has been considered for the improved delivery of various therapeutic agents, including drugs and genes. Indeed, liposomes and nanoparticles equipped with homing devices for the targeting of receptors over-expressed on the hepatic tissue have improved the treatment of various liver diseases. In this review, various nanotechnology approaches employed for the treatment/imaging of liver disease, either in preclinical or in clinic are discussed.

Superior preclinical efficacy of gemcitabine developed as chitosan nanoparticulate system.

Gemcitabine, an anticancer nucleoside analogue, undergoes rapid enzymatic degradation following intravenous injection. This necessitates the administration of a high order of doses to observe a required therapeutic response, while such high doses result in significant side effects. To improve the intravenous delivery of gemcitabine and simultaneously enhance its antitumor activity, we have investigated its incorporation into a drug nanoplatform based on the biodegradable polymer chitosan. Two gemcitabine loading methods have been investigated: (i) entrapment into the polymeric network (entrapment procedure): drug incorporation prior to the coacervation process that leads to the formation of gemcitabine-loaded chitosan (GemChit) nanoparticles; and (ii) surface deposition onto already formed chitosan nanoparticles after incubation in gemcitabine solution (adsorption procedure). The former method produced much higher gemcitabine loading values and a sustained release profile. The main factors determining the gemcitabine loading and release kinetic have also been analyzed. Following intravenous injection, the GemChit formulation displayed a significantly improved antitumor activity comparatively to free gemcitabine, which was further confirmed by histology and immunohistochemistry studies, suggesting the potential of this chitosan-based gemcitabine nanomedicine for the effective treatment of tumors.

Squalenoyl gemcitabine nanomedicine overcomes the low efficacy of gemcitabine therapy in pancreatic cancer.

Development of chemoresistance and rapid inactivation of gemcitabine (Gem), the standard therapy for advanced pancreatic cancer, are responsible of the major therapeutic failures. To overcome the above drawbacks we designed a novel nanomedicine strategy for Gem nanoparticle (NP) formulation based on squalene conjugation. The purpose was to investigate the antitumor efficacy of gemcitabine-squalene (SQ-Gem) NPs on chemoresistant and chemosensitive pancreatic adenocarcinoma models. Cell viability and apoptosis assays showed that SQ-Gem NPs displayed higher antiproliferative and cytotoxic effects, particularly in chemoresistant Panc1 tumor cells. In in vivo studies, compared to native Gem, SQ-Gem NPs decreased significantly the tumor growth, prevented tumor cell invasion, and prolonged the survival time of mice bearing orthotopic pancreatic tumors. These results correlate with a greater reduction of Ki-67 and induction of apoptosis. These findings demonstrate the feasibility of utilizing SQ-Gem NPs to make tumor cells more sensitive to Gem and thus provide an efficient new therapeutic alternative for pancreatic adenocarcinoma. FROM THE CLINICAL EDITOR: Pancreatic malignancies represent some of the most notoriously treatment resistant cancer varieties. This paper discusses a novel and promising nanotechnology-based treatment approach, currently at the basic science stage.

Novel nanoassemblies composed of squalenoyl-paclitaxel derivatives: synthesis, characterization, and biological evaluation.

Using the anticancer compound paclitaxel as a model drug, this study investigates the potential of the squalenoylation technology (i.e., bioconjugation with the natural lipid squalene) in addressing the drug ability and delivery issues of poorly soluble therapeutic agents. In this view, a variety of novel squalene-based prodrugs of the anticancer compound paclitaxel were synthesized, which produced nanoparticles in water. These prodrugs were obtained by covalent coupling of the paclitaxel 2'-hydroxyl group as direct ester, as well as with a succinate or a diglycolate ester as cleavable linker to the 1,1',2-tris-norsqualenoic acid. The hydrophilicity of these paclitaxel bioconjugates was increased by placing poly(ethylene glycol) chains of different lengths between paclitaxel and the squalenoyl moiety. All these prodrugs self-assembled into nanosized aggregates in aqueous solution as characterized by dynamic light scattering, atomic force microscopy, and transmission electron microscopy. The critical aggregation concentration was very low, ranging from 0.09 to 0.4 mg/L. Zeta potential measurements revealed that all squalenoyl-paclitaxel nanoassemblies (NA) held a global negative charge and appeared stable in water for several weeks as determined by particle size measurement. The release of paclitaxel from NA was evaluated in different conditions and in the presence of serum and depended on the nature of the linker used. Preliminary biological assessment showed that these squalenoyl-paclitaxel NA induced the formation of microtubule bundles in HT-29 and KB-31 cells, and additionally displayed notable cytotoxicity on a lung tumor cell line. Furthermore, the cytotoxic activity of these different prodrugs correlated closely with the observed linker stability. Overall, the squalenoylation nanotechnology opens up interesting perspectives for the development of injectable prodrugs of poorly soluble therapeutic compounds by addressing the associated physicochemical and biopharmaceutical challenges.

Squalenoyl nucleoside monophosphate nanoassemblies: new prodrug strategy for the delivery of nucleotide analogues.

4-(N)-1,1',2-trisnor-squalenoyldideoxycytidine monophosphate (SQddC-MP) and 4-(N)-1,1',2-trisnor-squalenoylgemcitabine monophosphate (SQdFdC-MP) were synthesized using phosphoramidite chemistry. These amphiphilic molecules self-assembled to about hundred nanometers size nanoassemblies in aqueous medium. Nanoassemblies of SQddC-MP displayed significant anti-HIV activity whereas SQdFdC-MP nanoassemblies displayed promising anticancer activity on leukemia cells. These results suggested that squalene conjugate of negatively charged nucleotide analogues efficiently penetrated within cells. Thus, we propose a new prodrug strategy for improved delivery of nucleoside analogues to ameliorate their biological efficacy.

Discovery of new hexagonal supramolecular nanostructures formed by squalenoylation of an anticancer nucleoside analogue.

In this study, the dynamically folded conformation of squalene (SQ) is taken advantage of to link this natural compound to the anticancer nucleoside analogue gemcitabine (gem) in order to achieve the spontaneous formation of nanoassemblies (SQgem) in water. Cryogenic transmission electron microscopy examination reveals particles (104 nm) with a hexagonal or multifaceted shape that display an internal structure made of reticular planes, each particle being surrounded by an external shell. X-ray diffraction evidences the hexagonal molecular packing of SQgem, resulting from the stacking of direct or inverse cylinders. The respective volumes of the gem and SQ molecules as well as molecular modeling of SQgem suggest the stacking of inverse hexagonal phases, in which the central aqueous core, consisting of water and gem molecules, is surrounded by SQ moieties. These SQgem nanoassemblies also exhibit impressively greater anticancer activity than gem against a solid subcutaneously grafted tumor, following intravenous administration. To our knowledge, this is the first demonstration of hexagonal phase organization with a SQ derivative.

Preclinical toxicology (subacute and acute) and efficacy of a new squalenoyl gemcitabine anticancer nanomedicine.

This study investigates 1) the anticancer efficacy of a new squalenoyl prodrug of gemcitabine (SQgem) in nanoassembly form compared with gemcitabine at equitoxic doses and 2) the subacute and acute preclinical toxicity of these compounds. The toxicity studies revealed that SQgem nanoassemblies, like gemcitabine, were toxic, and they led to dose-dependent mortality after daily i.v. injections for 1 week, irrespective of the route of administration. However, a 4- to 5-day spaced dosing schedule (injections on day 0, 4, 8, and 13) was proved to be safer in terms of weight loss and hematological and other toxicity. Using this spaced dosing schedule, SQgem nanoassemblies exhibited impressive anticancer activity in mice bearing L1210 leukemia because this treatment led to 75% long-term survivors. In contrast, at equitoxic doses, neither free gemcitabine nor cytarabine led to longterm survivors and all the mice of these groups died of the disease. Further toxicity studies performed at lethal doses by blood and serum analysis and organ weight determinations revealed that the hematological toxicity was the dose-limiting toxicity in both SQgem nanoassemblies and gemcitabine, whereas probable gastrointestinal toxicity was also associated with free gemcitabine. The SQgem nanoassemblies did not display hepatotoxicity, which is one of the clinically encountered toxicities of gemcitabine. To summarize, these preclinical studies demonstrated that the toxicological profile of new squalenoyl gemcitabine nanomedicine was not distinct from that of the parent gemcitabine, whereas it was much more potent than gemcitabine at equitoxic doses and cytarabine at clinically relevant doses. These data support the candidature of SQgem for clinical trials.

Squalenoylation favorably modifies the in vivo pharmacokinetics and biodistribution of gemcitabine in mice.

Gemcitabine (2',2'-difluorodeoxyribofuranosylcytosine; dFdC) is an anticancer nucleoside analog active against wide variety of solid tumors. However, this compound is rapidly inactivated by enzymatic deamination and can also induce drug resistance. To overcome the above drawbacks, we recently designed a new squalenoyl nanomedicine of dFdC [4-N-trisnorsqualenoyl-gemcitabine (SQdFdC)] by covalently coupling gemcitabine with the 1,1',2-trisnorsqualenic acid; the resultant nanomedicine displayed impressively greater anticancer activity compared with the parent drug in an experimental murine model. In the present study, we report that SQdFdC nanoassemblies triggered controlled and prolonged release of dFdC and displayed considerably greater t(1/2) (approximately 3.9-fold), mean residence time (approximately 7.5-fold) compared with the dFdC administered as a free drug in mice. It was also observed that the linkage of gemcitabine to the 1,1',2-trisnorsqualenic acid noticeably delayed the metabolism of dFdC into its inactive difluorodeoxyuridine (dFdU) metabolite, compared with dFdC. Additionally, the elimination of SQdFdC nanoassemblies was considerably lower compared with free dFdC, as indicated by lower radioactivity found in urine and kidneys, in accordance with the plasmatic concentrations of dFdU. SQdFdC nanoassemblies also underwent considerably higher distribution to the organs of the reticuloendothelial system, such as spleen and liver (p < 0.05), both after single- or multiple-dose administration schedule. Herein, this paper brings comprehensive pharmacokinetic and biodistribution insights that may explain the previously observed greater efficacy of SQdFdC nanoassemblies against experimental leukemia.

Simultaneous determination of gemcitabine and gemcitabine-squalene by liquid chromatography-tandem mass spectrometry in human plasma.

Gemcitabine-squalene is a new prodrug that self-organizes in water forming nanoassemblies. It exhibits better anti-cancer properties in vitro and in vivo than gemcitabine. A liquid chromatography/tandem mass spectrometry assay of gemcitabine-squalene and gemcitabine was developed in human plasma in order to quantitate gemcitabine and its squalene conjugate. After protein precipitation with acetonitrile/methanol (90/10, v/v), the compounds were analyzed by reversed-phase high performance liquid chromatography and detected by tandem mass spectrometry using multiple reaction monitoring. The method was linear over the concentration range of 10-10,000 ng/ml of human plasma for both compounds with an accuracy lower than 10.4% and a precision below 14.8%. The method showed a lower limit of quantitation of 10 ng/ml of human plasma for dFdC and dFdC-SQ. A preliminary in vivo study in mice was shown as application of the method as no significant difference between human and mice plasma for the analysis of dFdC and dFdC-SQ was demonstrated.

Drug delivery to tumours: recent strategies.

Despite several advancements in chemotherapy, the real therapy of cancer still remains a challenge. The development of new anti-cancer drugs for the treatment of cancer has not kept pace with the progress in cancer therapy, because of the nonspecific drug distribution resulting in low tumour concentrations and systemic toxicity. The main hindrance for the distribution of anti-cancer agents to the tumour site is the highly disorganized tumour vasculature, high blood viscosity in the tumour, and high interstitial pressure within the tumour tissue. Recently, several approaches such as drug modifications and development of new carrier systems for anti-cancer agents have been attempted to enhance their tumour reach. Approaches such as drug delivery through enhanced permeability and retention (EPR) effect have resulted in a significant improvement in concentration in tumours, while approaches such as drug-carrier implants and microparticles have resulted in improvement in local chemotherapy of cancer. This review discusses different strategies employed for the delivery of anti-cancer agents to tumours, such as through EPR effect, local chemotherapeutic approaches using drug delivery systems, and special strategies such as receptor-mediated delivery, pH-based carriers, application of ultrasound and delivery to resistant tumour cells and brain using nanoparticles.

Etoposide-loaded nanoparticles made from glyceride lipids: formulation, characterization, in vitro drug release, and stability evaluation.

The aim of the study was to prepare etoposide-loaded nanoparticles with glyceride lipids and then characterize and evaluate the in vitro steric stability and drug release characteristics and stability. The nanoparticles were prepared by melt emulsification and homogenization followed by spray drying of nanodispersion. Spray drying created powder nanoparticles with excellent redispersibility and a minimal increase in particle size (20-40 nm). Experimental variables, such as homogenization pressure, number of homogenization cycles, and surfactant concentration, showed a profound influence on the particle size and distribution. Spray drying of Poloxamer 407-stabilized nanodispersion lead to the formation of matrix-like structures surrounding the nanoparticles, resulting in particle growth. The in vitro steric stability test revealed that the lipid nanoparticles stabilized by sodium tauroglycocholate exhibit excellent steric stability compared with Poloxamer 407. All 3 glyceride nanoparticle formulations exhibited sustained release characteristics, and the release pattern followed the Higuchi equation. The spray-dried lipid nanoparticles stored in black polypropylene containers exhibited excellent long-term stability at 25 degrees C and room light conditions. Such stable lipid nanoparticles with in vitro steric stability can be a beneficial delivery system for intravenous administration as long circulating carriers for controlled and targeted drug delivery.

Enhanced tumour uptake of doxorubicin loaded poly(butyl cyanoacrylate) nanoparticles in mice bearing Dalton's lymphoma tumour.

The objective of this study is to enhance the delivery of Doxorubicin hydrochloride to Dalton's lymphoma solid tumour through poly(butyl cyanoacrylate) (PBC) nanoparticles. Doxorubicin loaded PBC (DPBC) nanoparticles were prepared by emulsion polymerization and characterized by particle size analysis, zeta potential and scanning electron microscopy. Doxorubicin HCl (Dox) and DPBC nanoparticles were radiolabeled with 99mTc by reduction method using stannous chloride and optimized the labeling parameters to obtain high labeling efficiency. The in vitro stability of 99mTc-labeled complexes was determined by DTPA and cysteine challenge test. The labeled complexes showed very low transchelation and high in vitro and serum stability. 99mTc labeled complexes of Dox and DPBC nanoparticles were administered subcutaneously below the Dalton's lymphoma tumour and biodistribution was studied. The distribution of DPBC nanoparticles to the blood, heart and organs of RES such as liver, lung and spleen was biphasic with a rapid initial distribution, followed by a significant decrease later at 6 h post-injection. The distribution of Dox to tissues was very low initially and increased significantly at 6 h post-injection indicating its accumulation at the injection site for a longer time. The concentration of DPBC nanoparticles was also found high in tissues at 6 h post-injection indicating their accumulation at the subcutaneous site and consequent disposition to tissues with time. A significantly high tumour uptake of DPBC nanoparticles (approximately 13 fold higher at 48 h post-injection) (P <0.001) was found compared to free Dox. The tumour concentrations of both Dox and DPBC nanoparticles increased with time indicating their slow penetration from the injection site into tumour. The concentration of DPBC nanoparticles in the femur bone in the tumour region was also significantly higher (P <0.001) than free Dox and increased with time. The study signifies the advantage of delivering Dox to Dalton's lymphoma through PBC nanoparticles by facilitating enhanced tumour uptake and prolonged tumour retention, which are expected to lead to greater therapeutic effect in the form of tumour regression.

Pharmacokinetics and biodistribution studies of Doxorubicin loaded poly(butyl cyanoacrylate) nanoparticles synthesized by two different techniques.

The aim of the study is to determine and compare the pharmacokinetics and tissue distribution of Doxorubicin (Dox) delivered as solution or through nanoparticles after intravenous (i.v.) and intraperitoneal (i.p.) injection. Doxorubicin loaded poly(butyl cyanoacrylate) nanoparticles were synthesized by dispersion polymerization (DP) and emulsion polymerization (EP) techniques. The drug loaded DP and EP nanoparticles were administered by i.v. or i.p. routes and the respective pharmacokinetics and tissue distribution were determined. Both types of nanoparticles significantly enhanced the elimination half-life (T(1/2)), mean residence time (MRT) AUC(0-8), AUC(0-infinity) and AUMC(0-8) of Dox in blood after i.v. injection. Dox delivered through DP nanoparticles rapidly disappeared from blood and distributed to the organs of reticuloendothelial system (RES). But, the clearance of Dox delivered through EP nanoparticles from blood was slower than this of the DP nanoparticles and Dox solution. After i.p. injection, the Dox loaded into DP nanoparticles quickly appeared in blood and undergone rapid distribution to the organs of RES, while the Dox loaded into EP nanoparticles absorbed slowly into blood and remained in the circulation for longer time. The absorption into blood of Dox delivered through DP and EP nanoparticles after i.p. injection was relatively rapid and higher than Dox solution. The T(1/2), MRT, AUC(0-8), AUC(0-infinity) and AUMC(0-8) of Dox in blood were significantly higher and the clearance (Cl) was lower than for the Dox solution after i.p. injection. The tissue concentrations of Dox delivered through nanoparticles after i.p. injection were significantly lower than after i.v. injection. The bioavailability (F) of Dox was greatly enhanced by DP (approximately 1.9 fold) and EP nanoparticles (approximately 2.12 fold) compared to Dox solution after i.p. injection. EP nanoparticles significantly enhanced the bioavailability, MRT, T(1/2), AUC(0-8), AUC(0-infinity) and AUMC(0-8) of Dox than DP nanoparticles. This signifies the advantage of EP nanoparticles in increasing the elimination half-life of Dox both after i.v. and i.p. injection and enhanced bioavailability after i.p. injection, which is expected to improve the therapeutic efficacy of Dox and reduce the Dox-associated systemic toxicity. Importantly, both DP and EP nanoparticles greatly reduced the distribution of Dox to heart both after i.v. and i.p. injection, suggesting their potential in reducing Dox-associated cardiotoxicity.

Drug delivery design for intravenous route with integrated physicochemistry, pharmacokinetics and pharmacodynamics: illustration with the case of taxane therapeutics.

This review is aimed at combining the published data on taxane formulations into a generalized Drug Delivery approach, starting from the physicochemistry and assessing its relationships with the pharmacokinetics, the biodistribution and the pharmacodynamics. Owing to the number and variety of taxane formulation designs, we considered this class of cytotoxic anticancer agents of particular interest to illustrate the concepts attached to this approach. According to the history of taxane development, we propose a classification as (i) "surfactant-based formulations" first generation, (ii) "surfactant-free formulations" second generation and (iii) "modulated pharmacokinetics drug delivery systems" third generation. Since our objective was to make the link between (i) the physicochemistry of the drug and carrier and (ii) the efficacy and safety of the drug in preclinical animal models and (iii) in human, we focused on the drug delivery technologies that were tested in clinic.

Squalene based nanocomposites: a new platform for the design of multifunctional pharmaceutical theragnostics.

This study reports the design of a novel theragnostic nanomedicine which combines (i) the ability to target a prodrug of gemcitabine to an experimental solid tumor under the influence of a magnetic field with (ii) the imaging of the targeted tumoral nodule. This concept is based on the inclusion of magnetite nanocrystals into nanoparticles (NPs) constructed by self-assembling molecules of the squalenoyl gemcitabine (SQgem) bioconjugate. The nanocomposites are characterized by an unusually high drug loading, a significant magnetic susceptibility, and a low burst release. When injected to the L1210 subcutaneous mice tumor model, these magnetite/SQgem NPs were magnetically guided, and they displayed considerably greater anticancer activity than the other anticancer treatments (magnetite/SQgem NPs nonmagnetically guided, SQgem NPs, or gemcitabine free in solution). The histology and immunohistochemistry investigation of the tumor biopsies clearly evidenced the therapeutic superiority of the magnetically guided nanocomposites, while Prussian blue staining confirmed their accumulation at the tumor periphery. The superior therapeutic activity and enhanced tumor accumulation has been successfully visualized using T(2)-weighted imaging in magnetic resonance imaging (MRI). This concept was further enlarged by (i) the design of squalene-based NPs containing the T(1) Gd(3+) contrast agent instead of magnetite and (ii) the application to other anticancer squalenoyls, such as, cisplatin, doxorubicin, and paclitaxel. Thus, by combining different anticancer medicines as well as contrast imaging agents in NPs, we open the door toward generic conceptual framework for cancer treatment and diagnosis. This new theragnostic nanotechnology platform is expected to have important applications in cancer therapy.

Liposomal squalenoyl-gemcitabine: formulation, characterization and anticancer activity evaluation.

A new prodrug of gemcitabine, based on the covalent coupling of squalene to gemcitabine (GemSQ), has been designed to enhance the anticancer activity of gemcitabine, a nucleoside analogue active against a wide variety of tumors. In the present study, the feasibility of encapsulating GemSQ into liposomes either PEGylated or non-PEGylated has been investigated. The in vivo anticancer activity of these formulations has been tested on subcutaneous grafted L1210wt leukemia model and compared to that of free gemcitabine. The liposomal GemSQ appears to be a potential delivery system for the effective treatment of tumors.

Squalene: A natural triterpene for use in disease management and therapy.

Squalene is a natural lipid belonging to the terpenoid family and a precursor of cholesterol biosynthesis. It is synthesized in humans and also in a wide array of organisms and substances, from sharks to olives and even bran, among others. Because of its significant dietary benefits, biocompatibility, inertness, and other advantageous properties, squalene is extensively used as an excipient in pharmaceutical formulations for disease management and therapy. In addition, squalene acts as a protective agent and has been shown to decrease chemotherapy-induced side-effects. Moreover, squalene alone exhibits chemopreventive activity. Although it is a weak inhibitor of tumor cell proliferation, it contributes either directly or indirectly to the treatment of cancer due to its potentiation effect. In addition, squalene enhances the immune response to various associated antigens, and it is therefore being investigated for vaccine delivery applications. Since this triterpene is well absorbed orally, it has been used to improve the oral delivery of therapeutic molecules. All of these qualities have rendered squalene a potentially interesting excipient for pharmaceutical applications, especially for the delivery of vaccines, drugs, genes, and other biological substances. This paper is the first review of its kind and offers greater insight into squalene's direct or indirect contribution to disease management and therapy.

Polymeric nanoparticulate system augmented the anticancer therapeutic efficacy of gemcitabine.

Gemcitabine hydrochloride is an anticancer nucleoside analogue indicated in clinic for the treatment of various solid tumors. Although this drug has been demonstrated to display anticancer activity against a wide variety of tumors, it is needed to be administered at high doses to elicit the required therapeutic response, simultaneously leading to severe adverse effects. We hypothesized that the efficient delivery of gemcitabine to tumors using a biodegradable carrier system could reduce the dose required to elicit sufficient therapeutic response. Thus, we have developed a nanoparticle formulation of gemcitabine suitable for parenteral administration based on the biodegradable polymer poly(octylcyanoacrylate) (POCA). The nanoparticles were synthesized by anionic polymerization of the corresponding monomer. Two drug loading methods were analyzed: the first one based on gemcitabine surface adsorption onto the preformed nanoparticles, and the second method being gemcitabine addition before the polymerization process leading to drug entrapment in the polymeric network. A detailed investigation of the capabilities of the polymer particles to load this drug is described. Gemcitabine entrapment into the polymer matrix yielded a higher drug loading and a slower drug release profile as compared with drug adsorption procedure. The main factors determining the gemcitabine incorporation to the polymer network were the nanoparticles preparation procedure, the monomer concentration, the surfactant concentration, the pH, and the drug concentration. The release kinetic of gemcitabine was found to be controlled by the pH and the type of drug incorporation. The cytotoxicity studies performed on L1210 tumor cells revealed a similar anticancer activity of the gemcitabine-loaded POCA (GPOCA) nanoparticle as free gemcitabine. Following intravenous administration into the mice bearing L1210 wt subcutaneous tumor, the GPOCA nanoparticles displayed significantly greater anticancer activity compared to free gemcitabine; this has been additionally confirmed by histology and immunohistochemistry studies, suggesting the potential of GPOCA for the efficient treatment of cancer.