Dodecanol-poly(d,l-lactic acid)-b-poly (ethylene glycol)-folate (Dol-PLA-PEG-FA) nanoparticles: Evaluation of cell cytotoxicity and selecting capability in vitro

Synthesis and Characterization of Folic Acid-Functionalized DPLA-co-PEG Nanomicelles for the Targeted Delivery of Letrozole

An effective treatment for hormone-dependent breast cancer is chemotherapy using cytotoxic agents such as letrozole (LTZ). However, most anticancer drugs, including LTZ, are classified as class IV biopharmaceuticals, which are associated with low water solubility, poor bioavailability, and significant toxicity. As a result, developing a targeted delivery system for LTZ is critical for overcoming these challenges and limitations. Here, biodegradable LTZ-loaded nanocarriers were synthesized by solvent emulsification evaporation using nanomicelles prepared with dodecanol-polylactic acid-co-polyethylene glycol (DPLA-co-PEG). Furthermore, cancer cell-targeting folic acid (FA) was conjugated into the nanomicelles to achieve a more effective and safer cancer treatment. During our investigation, DPLA-co-PEG and DPLA-co-PEG-FA displayed a uniform and spherical morphology. The average diameters of DPLA-co-PEG and DPLA-co-PEG-FA nanomicelles were 86.5 and 241.3 nm, respectively. Our preliminary data suggest that both nanoformulations were cytocompatible, with ≥90% cell viability across all concentrations tested. In addition, the amphiphilic nature of the nanomicelles led to high drug loading and dispersion in water, resulting in the extended release of LTZ for up to 50 h. According to the Higuchi model, nanomicelles functionalized with FA have a greater potential for the controlled delivery of LTZ into target cells. This model was confirmed experimentally, as LTZ-containing DPLA-co-PEG-FA was significantly and specifically more cytotoxic (up to 90% cell death) toward MCF-7 cells, a hormone-dependent human breast cancer cell line, when compared to free LTZ and LTZ-containing DPLA-co-PEG. Furthermore, a half-maximal inhibitory concentration (IC50) of 87 ± 1 nM was achieved when MCF-7 cells were exposed to LTZ-containing DPLA-co-PEG-FA, whereas higher doses of 125 ± 2 and 100 ± 2 nM were required for free LTZ and LTZ-containing DPLA-co-PEG, respectively. Collectively, DPLA-co-PEG-FA represents a promising nanosized drug delivery system to target controllably the delivery of drugs such as chemotherapeutics.

In Vitro Studies of Prednisolone Loaded PLGA Nanoparticles-Surface Functionalized With Folic Acid on Glioma and Macrophage Cell Lines

Background: Glucocorticoids are employed for their anti-inflammatory effects in treatingglioma, whose cells are known to overexpress the folate receptors. Some glucocorticoids haveshown inhibitory effects, but the efficacy of prednisolone when delivered via folate receptormediateduptake, has not been attempted. The study aimed to assess the efficacy of targeteddelivery of prednisolone on glioma cell lines like C6 and U87 via the folate receptors. Methods: Targeted delivery of prednisolone was achieved by initially conjugating folic acid (FA)to the di-block copolymer of polylactic acid (PLA) – polyethylene glycol (PEG). This moietycarrying di-block copolymer was incorporated on the surface of the drug-loaded poly lactic-coglycolicacid (PLGA) nanoparticle (NP) by employing the Interfacial Activity Assisted SurfaceFunctionalization (IAASF) technique. The NPs were evaluated for size, zeta potential, and drugloading. It was characterized using particle size analyser, SEM, 1H-NMR, and XRD. cell uptake,cytotoxicity, and anti-inflammatory activities were studied for various formulations. Results: The cytotoxicity assay indicated a high cell growth inhibitory effect of drug encapsulatedNPs with FA moiety as compared to free drug and NPs without the moiety for an incubationperiod of three, five, and six days. The growth-inhibitory effect of the free drug was short-lived,whereas FA functionalized NPs showed higher uptake and sustained inhibitory effect, and werealso able to significantly control the release of pro-inflammatory cytokines like tumour necrosisfactor-alpha (TNF-α) and nitric oxide (NO). Conclusion: Uptake, attenuation of pro-inflammatory signals, and the inhibitory effect ofprednisolone on the cells were more effective when targeted with the FA moiety on the surfaceof NPs as compared to free drug and NPs without the moiety.

Folate and Pegylated Aliphatic Polyester Nanoparticles for Targeted Anticancer Drug Delivery

Purpose

The use of chemotherapeutic agents to combat cancer is accompanied by high toxicity due to their inability to discriminate between cancer and normal cells. Therefore, cancer therapy research has focused on the targeted delivery of drugs to cancer cells. Here, we report an in vitro study of folate-poly(ethylene glycol)-poly(propylene succinate) nanoparticles (FA-PPSu-PEG-NPs) as a vehicle for targeted delivery of the anticancer drug paclitaxel in breast and cervical cancer cell lines.

Methods

Paclitaxel-loaded-FA-PPSu-PEG-NPs characterization was performed by in vitro drug release studies and cytotoxicity assays. The NPs cellular uptake and internalization mechanism were monitored by live-cell imaging in different cancer cell lines. Expression of folate receptor-α (FOLR1) was examined in these cell lines, and specific FOLR1-mediated entry of the FA-PPSu-PEG-NPs was investigated by free folic acid competition. Using inhibitors for other endocytic pathways, alternative, non-FOLR1 dependent routes for NPs uptake were also examined.

Results

Drug release experiments of Paclitaxel-loaded PPSu-PEG-NPs indicated a prolonged release of Paclitaxel over several days. Cytotoxicity of Paclitaxel-loaded PPSu-PEG-NPs was similar to free drug, as monitored in cancer cell lines. Live imaging of cells treated with either free Paclitaxel or Paclitaxel-loaded PPSu-PEG-NPs demonstrated tubulin-specific cell cycle arrest, with similar kinetics. Folate-conjugated NPs (FA-PPSu-PEG-NPs) targeted the FOLR1 receptor, as shown by free folic acid competition of the FA-PPSu-PEG-NPs cellular uptake in some of the cell lines tested. However, due to the differential expression of FOLR1 in the cancer cell lines, as well as the intrinsic differences between the different endocytic pathways utilized by different cell types, other mechanisms of nanoparticle cellular entry were also used, revealing that dynamin-dependent endocytosis and macropinocytosis pathways mediate, at least partially, cellular entry of the FA-PPSu-PEG NPs.

Conclusion

Our data provide evidence that Paclitaxel-loaded-FA-PPSu-PEG-NPs can be used for targeted delivery of the drug, FA-PPSu-PEG-NPs can be used as vehicles for other anticancer drugs and their cellular uptake is mediated through a combination of FOLR1 receptor-specific endocytosis, and macropinocytosis. The exploration of the different cellular uptake mechanisms could improve treatment efficacy or allow a decrease in dosage of anticancer drugs.

PLA-PEG-FA NPs for drug delivery system: Evaluation of carrier micro-structure, degradation and size-cell proliferation relationship

In this paper, the micro-structure of amphiphilic copolymer Polylactic acid-Polyethylene glycol-Folate (PLA-PEG-FA) was studied firstly by a differential scanning calorimetry (DSC). During the process of nanoparticles (NPs) preparation, we found good inter-structure consistency of polymer was the precondition for forming into stable NPs, and those with micro-phase separation structure were prepared of NPs within limits. Hemolytic test and CCK-8 assay results demonstrated the biotoxicity of both NPs and whose leaching liquor was far below related toxicity standards. Two kinds of cell, human breast cancer cell line (MCF-7) and human umbilical vein endothelial cells (EC), showed different manners in test of NPs size-cell proliferation relationship, respectively. Monitored by a nuclear magnetic resonance (NMR) and a gel permeation chromatography (GPC), the degradation behavior of NPs in aqueous solution indicated amide bond break more difficultly than ester bond, and FA classic proton peak disappeared in the third week, meanwhile lactic acid (LA) unit number became 25% of the initial. Finally the NPs was completely degraded in the eighth week. In the whole process, NPs underwent a change from compact to loose state. We hope these results will benefit to improve design of drug delivery system in nanomedicine, which could offer the selection rule for amphiphilic polymer NPs on material and size.

Folate-conjugated amphiphilic block copolymer micelle for targeted and redox-responsive delivery of doxorubicin

In this paper, novel folate-conjugated and redox-responsive crosslinked block copolymer was successfully synthesized for targeted and controlled release of doxorubicin (DOX) to cancer cells. Folate-conjugated poly(ethylene glycol)-b-copolycarbonates (FA-PEG-b-P(MAC-co-DTC)) and methoxy poly(ethylene glycol)-b-copolycarbonates (mPEG-b-P(MAC-co-DTC)) were firstly synthesized by enzymatic method. FA-PEG/mPEG-b-P(MAC-co-DTC)-SS was then obtained by further crosslinking reaction with cystamine. Non-conjugated crosslinked copolymer mPEG-b-P(MAC-co-DTC)-SS- and non-conjugated uncrosslinked copolymer mPEG-b-P(MAC-co-DTC) were also synthesized for comparison. All the amphiphlic copolymers could self-assemble to form nano-sized micelles which dispersed in spherical shape before and after DOX loading. The core crosslinking structure of FA-PEG/mPEG-b-P(MAC-co-DTC)-SS could improve the micellar stability and drug loading capacity, while in vitro release studies also showed more sustained drug release behavior which could be accelerated in reductive condition. Moreover, confocal laser scanning microscopy indicated that the conjugation of FA could enhance the cellular uptake efficiency obviously via FA-receptor-mediated endocytosis, and MTT assays demonstrated highly potent cytotoxic activity of FA-PEG/mPEG-b-P(MAC-co-DTC)-SS.

In vitro evaluation of antisense oligonucleotide functionalized core-shell nanoparticles loaded with α-tocopherol succinate

Antisense oligonucleotide (ASO)-conjugated-α-tocopherol succinate (TCS)-loaded-poly(lactic acid)-g-poly(ethylene glycol) nanoparticles (ASO-TCS-PLA-PEG NPs), with the ratio of polymer/TCS of 10:2.5, 10:5, 10:7 (w/w) were prepared for targeting cancer therapy. The amphiphilic PLA, amino terminated PEG graft copolymers were synthesized by ring opening polymerization reaction. Nanoparticles were produced by using double emulsion (w/o/w) solvent evaporation method. ASO-TCS-PLA-PEG NPs demonstrated satisfactory encapsulation and loading efficiency and size distribution. The short-term stability studies were carried out at 4 and 25 °C for 30 days to assess their mean particle size, polydispersity index and zeta potential. The cellular uptake and extended cytoplasmic retention of the NPs in A549 human lung carcinoma and L929 mouse fibroblast cells were examined by fluorescence and confocal microscopy. In human lung cancer cells, ASO-TCS-PLA-PEG NPs exhibited better cellular internalization, cytotoxicity and apoptotic and necrotic effects compared to healthy cell line, L929. These findings showed that ASO-modified nanoparticles could serve as a promising nanocarrier for targeted tumor cells.

Building the design, translation and development principles of polymeric nanomedicines using the case of clinically advanced poly(lactide(glycolide))-poly(ethylene glycol) nanotechnology as a model: An industrial viewpoint

The design of the first polymeric nanoparticles could be traced back to the 1970s, and has thereafter received considerable attention, as evidenced by the significant increase of the number of articles and patents in this area. This review article is an attempt to take advantage of the existing literature on the clinically tested and commercialized biodegradable PLA(G)A-PEG nanotechnology as a model to propose quality building and outline translation and development principles for polymeric nano-medicines. We built such an approach from various building blocks including material design, nano-assembly - i.e. physicochemistry of drug/nano-object association in the pharmaceutical process, and release in relevant biological environment - characterization and identification of the quality attributes related to the biopharmaceutical properties. More specifically, as envisaged in a translational approach, the reported data on PLA(G)A-PEG nanotechnology have been structured into packages to evidence the links between the structure, physicochemical properties, and the in vitro and in vivo performances of the nanoparticles. The integration of these bodies of knowledge to build the CMC (Chemistry Manufacturing and Controls) quality management strategy and finally support the translation to proof of concept in human, and anticipation of the industrialization takes into account the specific requirements and biopharmaceutical features attached to the administration route. From this approach, some gaps are identified for the industrial development of such nanotechnology-based products, and the expected improvements are discussed. The viewpoint provided in this article is expected to shed light on design, translation and pharmaceutical development to realize their full potential for future clinical applications.

Novel folated Pluronic/poly(lactic acid) nanoparticles for targeted delivery of paclitaxel

In vivo prolonged circulation time and enhanced tumor resistant ability of targeted PTX-loaded FA–Pluronic–PLA nanoparticles.

Synthesis of folate- pegylated polyester nanoparticles encapsulating ixabepilone for targeting folate receptor overexpressing breast cancer cells

The aim of this study was the preparation of novel polyester nanoparticles based on folic acid (FA)-functionalized poly(ethylene glycol)-poly(propylene succinate) (PEG-PPSu) copolymer and loaded with the new anticancer drug ixabepilone (IXA). These nanoparticles may serve as a more selective (targeted) treatment of breast cancer tumors overexpressing the folate receptor. The synthesized materials were characterized by (1)H-NMR, FTIR, XRD and DSC. The nanoparticles were prepared by a double emulsification and solvent evaporation method and characterized with regard to their morphology by scanning electron microscopy, drug loading with HPLC-UV and size by dynamic light scattering. An average size of 195 nm and satisfactory drug loading efficiency (3.5%) were observed. XRD data indicated that IXA was incorporated into nanoparticles in amorphous form. The nanoparticles exhibited sustained drug release properties in vitro. Based on in vitro cytotoxicity studies, the blank FA-PEG-PPSu nanoparticles were found to be non-toxic to the cells. Fluorescent nanoparticles were prepared by conjugating Rhodanine B to PEG-PPSu, and live cell, fluorescence, confocal microscopy was applied in order to demonstrate the ability of FA-PEG-PPSu nanoparticles to enter into human breast cancer cells expressing the folate receptor.

Folate-conjugated amphiphilic block copolymers for targeted and efficient delivery of doxorubicin

In this paper, novel biodegradable amphiphilic block copolymers based on folate-conjugated poly(ethylene glycol)-b-copolycarbonates (FA-PEG-b-P(MAC-co-DTC)) and methoxy poly(ethylene glycol)-b-copolycarbonates (mPEG-b-P(MAC-co-DTC)) were successfully synthesized for targeted and efficient delivery of doxorubicin (DOX) to cancer cells. Immobilized porcine pancreas lipase (IPPL) was employed as the catalyst to perform the ring-opening copolymerization in bulk, while the folate-conjugated poly(ethylene glycol) (FA-PEG) or methoxy poly(ethylene glycol) (mPEG) was used as the initiator. The resulting copolymers, characterized by (1)H NMR and GPC, could self-assemble to form nano-sized micelles in aqueous solution by dialysis method. P(MAC-co-DTC) acted as the hydrophobic core, thereby aggregating hydrophilic PEG chains as the outer shell with FA as targeting ligand located at the surface of the polymeric micelles. Transmission electron microscopy (TEM) observation showed that the micelles dispersed in spherical shape with nano-size before and after DOX loading. Both the FA-conjugated and non-conjugated block copolymers showed low cellular cytotoxicity. Furthermore, as compared to the non-conjugated copolymers, much more efficient cellular uptake of the FA-conjugated copolymers via FA-receptor-mediated endocytosis could be observed by confocal laser scanning microscopy (CLSM), while MTT assays also demonstrated highly potent cytotoxic activity against HeLa cells.

Receptor-based targeting of therapeutics

Receptor-based targeting of therapeutics may be a fascinating proposition to improve the therapeutic efficacy of encapsulated drugs. The development of safe and effective nanomedicines is a prerequisite in the current nanotechnological scenario. Currently, the surface engineering of nanocarriers has attracted great attention for targeted therapeutic delivery by selective binding of targeting ligand to the specific receptors present on the surface of cells. In this review, we have discussed the current status of various receptors such as transferrin, lectoferrin, lectin, folate, human EGF receptor, scavenger, nuclear and integrin, which are over-expressed on the surface of cancer cells; along with the relevance of targeted delivery systems such as nanoparticles, polymersomes, dendrimers, liposomes and carbon nanotubes. The review also focuses on the effective utilization of receptor-based targeted delivery systems for the management of cancer in effective ways by minimizing the drug-associated side effects and improving the therapeutic efficacy of developed nano-architectures.

Concepts and practices used to develop functional PLGA-based nanoparticulate systems

The functionality of bare polylactide-co-glycolide (PLGA) nanoparticles is limited to drug depot or drug solubilization in their hard cores. They have inherent weaknesses as a drug-delivery system. For instance, when administered intravenously, the nanoparticles undergo rapid clearance from systemic circulation before reaching the site of action. Furthermore, plain PLGA nanoparticles cannot distinguish between different cell types. Recent research shows that surface functionalization of nanoparticles and development of new nanoparticulate dosage forms help overcome these delivery challenges and improve in vivo performance. Immense research efforts have propelled the development of diverse functional PLGA-based nanoparticulate delivery systems. Representative examples include PEGylated micelles/nanoparticles (PEG, polyethylene glycol), polyplexes, polymersomes, core-shell-type lipid-PLGA hybrids, cell-PLGA hybrids, receptor-specific ligand-PLGA conjugates, and theranostics. Each PLGA-based nanoparticulate dosage form has specific features that distinguish it from other nanoparticulate systems. This review focuses on fundamental concepts and practices that are used in the development of various functional nanoparticulate dosage forms. We describe how the attributes of these functional nanoparticulate forms might contribute to achievement of desired therapeutic effects that are not attainable using conventional therapies. Functional PLGA-based nanoparticulate systems are expected to deliver chemotherapeutic, diagnostic, and imaging agents in a highly selective and effective manner.