Enhanced cellular uptake of folic acid–conjugated PLGA–PEG nanoparticles loaded with vincristine sulfate in human breast cancer

Research on the loading and release kinetics of the vincristine sulfate liposomes and its anti-breast cancer activity

Vincristine (VCR), as a cytotoxic drug, is used clinically to treat acute lymphatic leukemia and breast cancer, and commonly used clinically as vincristine sulfate (VCRS). However, its clinical use is limited by unpredictable pharmacologic characteristics, a narrow therapeutic index, and neurotoxicity. The pH gradient method was used for active drug loading of VCRS, and the process route mainly includes the preparation of blank liposomes and drug-loaded liposomes. VCRS liposomes had suitable particle size, high encapsulation efficiency and good stability. The loading and release kinetics of VCRS liposomes were explored. By calculating the changes of encapsulation efficiency with time at different temperatures, it was confirmed that the drug-loading process of liposomes exhibited a first-order kinetic feature, and the activation energy required for the reaction was determined as 20.6 kcal/mol. The release behavior at different pH was also investigated, and it was demonstrated that the release behavior conformed to the first-order model, suggesting that the release mechanism of VCRS was simple transmembrane diffusion. VCRS liposomes also enhanced in vitro and in vivo antitumor activity. Thus, VCRS liposomes showed great potential for VCRS delivery, and the loading and release kinetics were well researched to provide a reference for investigating active drug loading liposomes.

Polymer-based drug delivery systems for anticancer drugs: A systematic review

Recent advances in nanotechnology sciences lead to the development of new treatment approaches for various diseases such as cancer. Nanotechnology advances can potentially minimize the side effects of drugs through the employment of effective and controlled drug delivery systems (DDSs). Polymers are optimal tools providing drug delivery mechanisms through the unique features of pharmacokinetics, circulation time, biocompatibility, and biodegradability. This systematic review aimed to evaluate polymer-based DDSs for anticancer drugs and their various therapeutic applications in cancer treatment. This study was conducted with no time limitation by November 2021. Related articles were collected through a deep search in English and Persian databases of SID, MagIran, Scopus, Web Of Science (WoS), PubMed, Science Direct, and Google Scholar. Keywords included drug delivery system, anticancer agent, polymeric nanostructure-based drug delivery, polymer-based drug delivery, and polymeric system. As the results showed, polymeric nanoparticles (PNPs) have influential roles in cancer treatment than conventional chemotherapy procedures. PNPs can reduce cytotoxicity following chemotherapy drug administration, improve the solubility characteristics of these therapeutic agents and inhibit the rate of tumor growth.

Progress in the drug encapsulation of poly(lactic-co-glycolic acid) and folate-decorated poly(ethylene glycol)-poly(lactic-co-glycolic acid) conjugates for selective cancer treatment

Poly(lactic-co-glycolic acid) (PLGA) is a US Food and Drug Administration (FDA)-approved polymer used in humans in the forms of resorbable sutures, drug carriers, and bone regeneration materials. Recently, PLGA-based conjugates have been extensively investigated for cancer, which is the second leading cause of death globally. This article presents an account of the literature on PLGA-based conjugates, focusing on their chemistries, biological activity, and functions as targeted drug carriers or sustained drug controllers for common cancers (e.g., breast, prostate, and lung cancers). The preparation and drug encapsulation of PLGA nanoparticles and folate-decorated poly(ethylene glycol)-poly(lactic-co-glycolic acid) (FA-PEG-PLGA) conjugates are discussed, along with several representative examples. Particularly, the reactions used for preparing drug-conjugated PLGA and FA-PEG-PLGA are emphasized, with the associated chemistries involved in the formation of structures and their biocompatibility with internal organs. This review provides a deeper understanding of the constituents and interactions of PLGA-conjugated materials to ensure successful conjugation in PLGA material design and the subsequent biomedical applications.

Adenosine Conjugated Docetaxel Nanoparticles—Proof of Concept Studies for Non-Small Cell Lung Cancer

Non-small cell lung cancer, a molecularly diverse disease, is the most prevalent cause of cancer mortality globally. Increasing understanding of the clinicopathology of the disease and mechanisms of tumor progression has facilitated early detection and multimodal care. Despite the advancements, survival rates are extremely low due to non-targeted therapeutics and correspondingly increased risk of metastasis. At some phases of cancer, patients need to face the ghost of chemotherapy. It is a difficult decision near the end of life. Such treatments have the capability to prolong survival or reduce symptoms, but can cause serious adverse effects, affecting quality of life of the patient. It is evident that many patients do not die from burden of the disease alone, but they die due to the toxic effect of treatment. Thus, increasing the efficacy is one aspect and decreasing the toxicity is another critical aspect of cancer formulation design. Through our current research, we tried to uncover both mentioned potentials of the formulation. Therefore, we designed actively targeted nanoparticles for improved therapeutics considering the overexpression of adenosine (ADN) receptors on non-small cell lung cancer (NSCLC) cells. Docetaxel (DTX), an essential therapeutic as part of combination therapy or as monotherapy for the treatment of NSCLC, was encapsulated in biodegradable poly(lactic-co-glycolic acid) nanoparticles. ADN was conjugated on the surface of nanoparticles using EDC-NHS chemistry. The particles were characterized in vitro for physicochemical properties, cellular uptake, and biocompatibility. The size and zeta potential of DTX nanoparticles (DPLGA) were found to be 138.4 ± 5.45 nm and −16.7 ± 2.3 mV which were found to change after ADN conjugation. The size was increased to 158.2 ± 6.3 nm, whereas zeta potential was decreased to −11.7 ± 1.4 mV for ADN-conjugated DTX nanoparticles (ADN-DPLGA) indicative of surface conjugation. As observed from transmission electron microscopy (TEM), the nanoparticles were spherical and showed no significant change in encapsulation efficiency even after surface conjugation. Careful and systematic optimization leads to ADN-conjugated PLGA nanoparticles having distinctive characteristic features such as particle size, surface potential, encapsulation efficacy, etc., that may play crucial roles in the fate of nanoparticles (NPs). Consequently, higher cellular uptake in the A549 lung cancer cell line was exhibited by ADN-DPLGA compared to DPLGA, illustrating the role of ADN receptors (ARs) in facilitating the uptake of NPs. Further in vivo pharmacokinetics and tissue distribution experiments revealed prolonged circulation in plasma and significantly higher lung tissue distribution than in other organs, dictating the targeting potential of the developed formulation over naïve drug and unconjugated formulations. Further, in vivo acute toxicity was examined using multiple parameters for non-toxic attributes of the developed formulation compared to other non-targeted organs. Further, it also supports the selection of biocompatible polymers in the formulation. The current study presents a proof-of-concept for a multipronged formulation technology strategy that might be used to maximize anticancer therapeutic responses in the lungs in the treatment of NSCLC. An improved therapeutic and safety profile would help achieve maximum efficacy at a reduced dose that would eventually help reduce the toxicity.

Receptor-Mediated Targeted Delivery of Surface-ModifiedNanomedicine in Breast Cancer: Recent Update and Challenges

Breast cancer therapeutic intervention continues to be ambiguous owing to the lack of strategies for targeted transport and receptor-mediated uptake of drugs by cancer cells. In addition to this, sporadic tumor microenvironment, prominent restrictions with conventional chemotherapy, and multidrug-resistant mechanisms of breast cancer cells possess a big challenge to even otherwise optimal and efficacious breast cancer treatment strategies. Surface-modified nanomedicines can expedite the cellular uptake and delivery of drug-loaded nanoparticulate constructs through binding with specific receptors overexpressed aberrantly on the tumor cell. The present review elucidates the interesting yet challenging concept of targeted delivery approaches by exploiting different types of nanoparticulate systems with multiple targeting ligands to target overexpressed receptors of breast cancer cells. The therapeutic efficacy of these novel approaches in preclinical models is also comprehensively discussed in this review. It is concluded from critical analysis of related literature that insight into the translational gap between laboratories and clinical settings would provide the possible future directions to plug the loopholes in the process of development of these receptor-targeted nanomedicines for the treatment of breast cancer.

Developments in drug delivery of bioactive alkaloids derived from traditional Chinese medicine

The bioactive alkaloids (e.g. vincristine, hydroxycamptothecin, ligustrazine, and so on) from traditional Chinese medicine (TCM) have exerted potent efficacies (e.g. anti-tumor, anti-inflammation, immunosuppression, etc.). However, a series of undesirable physicochemical properties (like low solubility and weak stability) and baneful pharmacokinetic (PK) profiles (e.g. low bioavailability, short half time, rapid clearance, etc.) have severely restricted their applications in clinic. In addition, some side effects (like cumulative toxicities caused by high-frequency administration and their own toxicities) have recently been reported and also confined their clinical uses. Therefore, developments in drug delivery of such alkaloids are of significance in improving their drug-like properties and, thus, treatment efficiencies in clinic. Strategies, including (i) specific delivery via liposomes; (ii) sustained delivery via nanoparticles, gels, and emulsions; and (iii) transdermal delivery via ethosomes, solid lipid nanoparticles, and penetrating enhancers, have been reported to improve the pharmacokinetic and physicochemical characters of problematic TCM alkaloids, decline their adverse effects, and thus, boost their curative efficacies. In this review, the recent reports in this field were comprehensively summarized with the aim of providing an informative reference for relevant readers.

Phase-shift, targeted nanoparticles for ultrasound molecular imaging by low intensity focused ultrasound irradiation

Purpose

Ultrasound (US) molecular imaging provides a non-invasive way to visualize tumor tissues at molecular and cell levels and could improve diagnosis. One problem of using US molecular imaging is microbubbles challenges, including instability, short circulation time, and poor loading capacity and penetrability. It is urgent to design new acoustic contrast agents and new imaging methods to facilitate tumor-targeted imaging. In this study, phase-shift poly lactic-co-glycolic acid (PLGA) nanoparticles modified with folate as an efficient US molecular probe were designed and the long–term targeted imaging was achieved by low-intensity focused US (LIFU) irradiation.

Methods

A new 5-step method and purification procedure was carried out to obtain uniform folic acid polyethylene glycol PLGA (PLGA-PEG-FA), the structure of which was confirmed by ¹H nuclear magnetic resonance spectroscopy and thin-layer chromatography. Perflenapent (PFP) was wrapped in PLGA-PEG-FA by a double emulsion solvent evaporation method to obtain PFP/PLGA-PEG-FA nanoparticles. The targeted ability of the resulting nanoparticles was tested in vivo and in vitro. LIFU irradiation can irritate nanoparticle phase-shift to enhance tumor imaging both in vivo and in vitro.

Results

PLGA-PEG-FA was a light yellow powder with a final purity of at least 98%, the structure of which was confirmed by ¹H nuclear magnetic resonance spectroscopy and thin-layer chromatography. Highly dispersed PFP/PLGA-PEG-FA nanoparticles with spherical morphology have an average diameter of 280.9±33.5 nm, PFP load efficiency of 59.4%±7.1%, and shells, thickness of 28±8.63 nm. The nanoparticles can specifically bind to cells expressing high folate receptor both in vivo and in vitro. Ultrasonic imaging was significantly enhanced in vitro and in vivo by LIFU irradiation. The retention time was significantly prolonged in vivo.

Conclusion

Phase-shift PFP/PLGA-PEG-FA nanoparticles induced by LIFU can significantly enhance ultrasonic imaging, specifically targeting tumors expressing folate receptor. As a potential targeting acoustic molecular probe, PFP/PLGA-PEG-FA nanoparticles can be used to achieve targeted localization imaging.

Nucleosome-inspired nanocarrier obtains encapsulation efficiency enhancement and side effects reduction in chemotherapy by using fullerenol assembled with doxorubicin

Chemodrugs have been widely used to treat cancer; however, the chemotherapy usually leads to serious side effects and failure. Various nanomaterials and strategies have been explored for drug delivery to improve the efficacy of chemodrugs. One key to loading chemodrugs onto a nano-delivery system is enhancement of the encapsulation efficiency, especially for polymeric nanoparticles being loaded with hydrophilic drugs. Inspired by the ability of eukaryote to package millions of genes in the nucleus wrapping and condensing DNA around histones to form chromosomes, here we developed a karyon-like hybrid nanoparticle to achieve ultra-high encapsulation of doxorubicin (Dox) with reduced side effects. We utilized fullerenol as a "histone", packaged a great number of Dox, and used PEG-PLGA as the "karyotheca" coating the "nucleosome" (fullerenol and Dox complex) to stabilize the complex. It is noteworthy that the encapsulation efficiency of Dox in the polymeric micelles was increased from ∼5% to ∼79%. What's more, the biomimetic-inspired delivery system significantly reduced the chemodrug side effects by utilizing the radical scavenging ability of fullerenol. This novel drug-delivery design approach provides useful insights for improving the applicability of fullerenol in drug delivery systems for cancer therapy.

Vincristine and ɛ-viniferine-loaded PLGA-b-PEG nanoparticles: pharmaceutical characteristics, cellular uptake and cytotoxicity

The objective of this study was to prepare the ɛ-viniferine and vincristine-loaded PLGA-b-PEG nanoparticle and to investigate advantages of these formulations on the cytotoxicity of HepG2 cells. Prepared nanoparticle has shown a homogeneous distribution with 113 ± 0.43 nm particle size and 0.323 ± 0.01 polydispersity index. Zeta potential was determined as -35.03 ± 1.0 mV. The drug-loading percentages were 6.01 ± 0.23 and 2.01 ± 0.07 for ɛ-viniferine and vincristine, respectively. The cellular uptake efficiency of coumarin-6-loaded nanoparticles was increased up to 87.8% after 4 h. Nanoparticles loaded with high concentrations of both drugs showed a cytotoxic effect on HepG2 cells, having the percentage of cell viability of between 43.23% and 47.37%. Unfortunately, the percentage of apoptotic cells after treated with drugs-loaded nanaoparticles (10.93%) was similar to free forms of drugs (12.1%) that might be due to low ɛ-viniferine release in biological pH at 24 h.

Intracellular delivery and ultrasonic activation of folate receptor-targeted phase-change contrast agents in breast cancer cells in vitro

Breast cancer is a diverse and complex disease that remains one of the leading causes of death among women. Novel, outside-of-the-box imaging and treatment methods are needed to supplement currently available technologies. In this study, we present evidence for the intracellular delivery and ultrasound-stimulated activation of folate receptor (FR)-targeted phase-change contrast agents (PCCAs) in MDA-MB-231 and MCF-7 breast cancer cells in vitro. PCCAs are lipid-coated, perfluorocarbon-filled particles formulated as nanoscale liquid droplets capable of vaporization into gaseous microbubbles for imaging or therapy. Cells were incubated with 1:1 decafluorobutane (DFB)/octafluoropropane (OFP) PCCAs for 1h, imaged via confocal microscopy, exposed to ultrasound (9MHz, MI=1.0 or 1.5), and imaged again after insonation. FR-targeted PCCAs were observed intracellularly in both cell lines, but uptake was significantly greater (p<0.001) in MDA-MB-231 cells (93.0% internalization at MI=1.0, 79.5% at MI=1.5) than MCF-7 cells (42.4% internalization at MI=1.0, 35.7% at MI=1.5). Folate incorporation increased the frequency of intracellular PCCA detection 45-fold for MDA-MB-231 cells and 7-fold for MCF-7 cells, relative to untargeted PCCAs. Intracellularly activated PCCAs ranged from 500nm to 6μm (IQR=800nm-1.5μm) with a mean diameter of 1.15±0.59 (SD) microns. The work presented herein demonstrates the feasibility of PCCA intracellular delivery and activation using breast cancer cells, illuminating a new platform toward intracellular imaging or therapeutic delivery with ultrasound.

Expression of high affinity folate receptor in breast cancer brain metastasis

High affinity folate receptor (HFR) can be overexpressed in breast cancer and is associated with poor prognosis, however the expression in breast cancer brain metastases (BCBM) is unknown. The aim of this study was to analyze the rate of HFR expression in BCBM and its role in the prognosis of this high-risk cohort. We analyzed 19 brain metastasis (BM) and 13 primary tumors (PT) from a total of 25 patients. HFR status was assessed by immunohistochemistry. Median follow-up was 4.2 years (range 0.6-18.5). HFR was positive in 4/19 BM (21.1%) and in 1/13 PT (7.7%). Positive samples had low H-scores (range 1-50). 56% of patients had apocrine differentiation. OS was similar between patients with positive HFR (median OS 48 months) and negative HFR (median OS 69 months) (P = 0.25); and between patients with apocrine differentiation (median OS 63 months) and those without apocrine differentiation (median OS 69 months) (P = 0.49). To the best of our knowledge, this is the first analysis of HFR expression in BCBM. While previous studies associated the presence of HFR with worse prognosis; in our cohort HFR was positive in only 21.1% of BM with low levels of positivity. Neither HFR nor apocrine features had impact in OS.

The influence of mPEG-PCL and mPEG-PLGA on encapsulation efficiency and drug-loading of SN-38 NPs

The influence of mPEG-PCL and mPEG-PLGA on encapsulation efficiency and drug-loading of nanoparticles was very important. SN-38 NPs were prepared from a series of diblock copolymers: mPEG1000-PLGA2000, mPEG2000-PCLs, mPEG5000-PCLs, mPEG2000-PLGAs, and mPEG5000-PLGAs by the thin film-hydration method. The prepared nanoparticles were characterized by morphology, size, encapsulation efficiency, drug-loading, and in vitro release behavior. This experiment suggested that the encapsulation efficiency and drug-loading of SN-38 NPs were attained the maximum values when the ratio of hydrophilic to hydrophobic block was between 1:2 and 1:3.

Breast Cancer: Conventional Diagnosis and Treatment Modalities and Recent Patents and Technologies

Breast cancer is the most prevalent cancer among women worldwide. However, increased survival is due to the dramatic advances in the screening methods, early diagnosis, and breakthroughs in treatments. Over the course of the last decade, many acquisitions have taken place in this critical field of research in the pharmaceutical industry. Advances in molecular biology and pharmacology aided in better understanding of breast cancer, enabling the design of smarter therapeutics able to target cancer and respond to its microenvironment efficiently. Patents and research papers investigating diagnosis and treatment strategies for breast cancer using novel technologies have been surveyed for the past 15 years. Various nanocarriers have been introduced to improve the therapeutic efficacy of anticancer drugs, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. This review provides an overview of breast cancer, conventional therapy, novel technologies in the management of breast cancer, and rational approaches for targeting breast cancer.

HIGHLIGHTS

Breast cancer is the most common cancer in women worldwide. However, survival rates vary widely, optimistically heading toward a positive trend. Increased survival is due to the drastic shift in the screening methods, early diagnosis, and breakthroughs in treatments.Different strategies of breast cancer classification and staging have evolved over the years. Intrinsic (molecular) subtyping is essential in clinical trials and well understanding of the disease.Many novel technologies are being developed to detect distant metastases and recurrent disease as well as to assess response to breast cancer management.Intensive research efforts are actively ongoing to take novel breast cancer therapeutics to potential clinical application.Most of the recent research papers and patents discuss one of the following strategies: the development of new drug entities that specifically target the breast tumor cells; tailor designing a novel carrier system that can multitask and multifunction as a drug carrier, targeting vehicle and even as a diagnostic tool, direct conjugation of a therapeutic drug moiety with a targeting moiety, diagnostic moiety or pharmacokinetics altering moiety; or the use of innovative nontraditional approaches such as genetic engineering, stem cells, or vaccinations.

Nanodrug delivery systems: a promising technology for detection, diagnosis, and treatment of cancer

Nanotechnology has enabled the development of novel therapeutic and diagnostic strategies, such as advances in targeted drug delivery systems, versatile molecular imaging modalities, stimulus responsive components for fabrication, and potential theranostic agents in cancer therapy. Nanoparticle modifications such as conjugation with polyethylene glycol have been used to increase the duration of nanoparticles in blood circulation and reduce renal clearance rates. Such modifications to nanoparticle fabrication are the initial steps toward clinical translation of nanoparticles. Additionally, the development of targeted drug delivery systems has substantially contributed to the therapeutic efficacy of anti-cancer drugs and cancer gene therapies compared with nontargeted conventional delivery systems. Although multifunctional nanoparticles offer numerous advantages, their complex nature imparts challenges in reproducibility and concerns of toxicity. A thorough understanding of the biological behavior of nanoparticle systems is strongly warranted prior to testing such systems in a clinical setting. Translation of novel nanodrug delivery systems from the bench to the bedside will require a collective approach. The present review focuses on recent research efforts citing relevant examples of advanced nanodrug delivery and imaging systems developed for cancer therapy. Additionally, this review highlights the newest technologies such as microfluidics and biomimetics that can aid in the development and speedy translation of nanodrug delivery systems to the clinic.

Platinum folate nanoparticles toxicity: cancer vs. normal cells

Almost for two decades metallic nanoparticles are successfully used for cancer detection, imaging and treatment. Due to their high electron density they can be easily observed by electron microscopy and used in laser and radiofrequency therapy as energy releasing agents. However, the limitation for this practice is an inability to generate tumor-specific heating in a minimally invasive manner to the healthy tissue. To overcome this restraint we proposed to use folic acid coated metallic nanoparticles and determine whether they preferentially penetrate cancer cells. We developed technique for synthesizing platinum nanoparticles using folic acid as stabilizing agent which produced particles of relatively narrow size distribution, having d=2.3 ± 0.5 nm. High resolution TEM and zeta potential analysis indicated that the particles produced by this method had a high degree of crystalline order with no amorphous outer shell and a high degree of colloidal stability. The keratinocytes and mammary breast cells (cancer and normal) were incubated with platinum folate nanoparticles, and the results showed that the IC50 was significantly higher for the normal cells than the cancer cells in both cases, indicating that these nanoparticles preferentially target the cancer cells. TEM images of thin sections taken from the two types of cells indicated that the number of vacuoles and morphology changes after incubation with nanoparticles was also larger for the cancer cells in both types of tissue studied. No preferential toxicity was observed when folic acid receptors were saturated with free folic acid prior to exposure to nanoparticles. These results confirm our hypothesis regarding the preferential penetration of folic acid coated nanoparticles to cancer cells due to receptor mediated endocytosis.

Nanotechnology-based approaches in anticancer research

Cancer is a highly complex disease to understand, because it entails multiple cellular physiological systems. The most common cancer treatments are restricted to chemotherapy, radiation and surgery. Moreover, the early recognition and treatment of cancer remains a technological bottleneck. There is an urgent need to develop new and innovative technologies that could help to delineate tumor margins, identify residual tumor cells and micrometastases, and determine whether a tumor has been completely removed or not. Nanotechnology has witnessed significant progress in the past few decades, and its effect is widespread nowadays in every field. Nanoparticles can be modified in numerous ways to prolong circulation, enhance drug localization, increase drug efficacy, and potentially decrease chances of multidrug resistance by the use of nanotechnology. Recently, research in the field of cancer nanotechnology has made remarkable advances. The present review summarizes the application of various nanotechnology-based approaches towards the diagnostics and therapeutics of cancer.

Folate receptor targeted 17-allylamino-17-demethoxygeldanamycin (17-AAG) loaded polymeric nanoparticles for breast cancer

Low water solubility and hepatotoxicity limited the clinical use of 17-allylamino-17-demethoxy geldanamycin (17-AAG), an inhibitor of heat shock protein 90 (HSP90). Folate targeted polylactide-co-glycolide-polyethylene glycol-folic acid (PLGA-PEG-FA) nanoparticles containing 17-AAG were prepared and characterized. Cellular uptake and in vitro cytotoxicity of the prepared nanoparticles were determined in MCF-7 human breast cancer cells. The particle size of 17-AAG loaded folate targeted nanoparticles was 238.67±3.52 nm, drug loading was 8.25±2.49% and about 80% of drug was released from the nanoparticles over 10 days. Cellular uptake studies showed much higher intracellular uptake of folate targeted nanoparticle as compared to nontargeted nanoparticles. Cytotoxicity study showed 2 fold increase (P<0.05, n=3) in the cytotoxicity of folate targeted nanoparticle in comparison to free drug or nontargeted nanoparticles. Due to their targeting ability, nanometer size, high drug loading and controlled release behavior, 17-AAG loaded PLGA-PEG-FA nanoparticles might be developed as a targeted delivery system for breast and other cancer treatment.