Enhanced intracellular delivery and controlled drug release of magnetic PLGA nanoparticles modified with transferrin

Surface-functionalised polymeric nanoparticles for breast cancer treatment: processes and advances

The World Health Organization (WHO) reported that of all the non-communicable diseases, cancer is considered the second cause of death worldwide. This has driven the big pharma companies to prioritise anticancer products in their pipeline. In addition, research has focused on exploration of new anticancer molecules and design of suitable dosage forms to achieve effective drug delivery to the tumour site. Nanotechnology is a valuable tool to build nano delivery systems with controlled and targeted drug release properties. Nanoparticles can be fabricated by robust, scalable and economic techniques using various polymers. Moreover, specific functional groups can be introduced to the surface of nanoparticles enabling targeting to a specific tissue; besides, they exhibit versatile drug release patterns according to the rate of polymer degradation. This review outlines the processes and advances in surface functionalisation of nanoparticles employed for treatment of breast cancer. The therapeutic molecules, the polymers used to fabricate nanoparticles, the techniques used to prepare the nanoparticles have been reviewed with a focus on the processes employed to functionalise these nanoparticles with suitable ligands to target different types of breast cancer.

Development and characterization of lipid nanocapsules loaded with iron oxide nanoparticles for magnetic targeting to the blood-brain barrier

Brain drug delivery is severely hindered by the presence of the blood-brain barrier (BBB). Its functionality relies on the interactions of the brain endothelial cells with additional cellular constituents, including pericytes, astrocytes, neurons, or microglia. To boost brain drug delivery, nanomedicines have been designed to exploit distinct delivery strategies, including magnetically driven nanocarriers as a form of external physical targeting to the BBB. Herein, a lipid-based magnetic nanocarrier prepared by a low-energy method is first described. Magnetic nanocapsules with a hydrodynamic diameter of 256.7 ± 8.5 nm (polydispersity index: 0.089 ± 0.034) and a ξ-potential of -30.4 ± 0.3 mV were obtained. Transmission electron microscopy-energy dispersive X-ray spectroscopy analysis revealed efficient encapsulation of iron oxide nanoparticles within the oily core of the nanocapsules. Both thermogravimetric analysis and phenanthroline-based colorimetric assay showed that the iron oxide percentage in the final formulation was 12 wt.%, in agreement with vibrating sample magnetometry analysis, as the specific saturation magnetization of the magnetic nanocapsules was 12% that of the bare iron oxide nanoparticles. Magnetic nanocapsules were non-toxic in the range of 50-300 μg/mL over 72 h against both the human cerebral endothelial hCMEC/D3 and Human Brain Vascular Pericytes cell lines. Interestingly, higher uptake of magnetic nanocapsules in both cell types was evidenced in the presence of an external magnetic field than in the absence of it after 24 h. This increase in nanocapsules uptake was also evidenced in pericytes after only 3 h. Altogether, these results highlight the potential for magnetic targeting to the BBB of our formulation.

Improving the Efficacy of Common Cancer Treatments via Targeted Therapeutics towards the Tumour and Its Microenvironment

Cancer is defined as the uncontrolled proliferation of heterogeneous cell cultures in the body that develop abnormalities and mutations, leading to their resistance to many forms of treatment. Left untreated, these abnormal cell growths can lead to detrimental and even fatal complications for patients. Radiation therapy is involved in around 50% of cancer treatment workflows; however, it presents significant recurrence rates and normal tissue toxicity, given the inevitable deposition of the dose to the surrounding healthy tissue. Chemotherapy is another treatment modality with excessive normal tissue toxicity that significantly affects patients' quality of life. To improve the therapeutic efficacy of radiotherapy and chemotherapy, multiple conjunctive modalities have been proposed, which include the targeting of components of the tumour microenvironment inhibiting tumour spread and anti-therapeutic pathways, increasing the oxygen content within the tumour to revert the hypoxic nature of the malignancy, improving the local dose deposition with metal nanoparticles, and the restriction of the cell cycle within radiosensitive phases. The tumour microenvironment is largely responsible for inhibiting nanoparticle capture within the tumour itself and improving resistance to various forms of cancer therapy. In this review, we discuss the current literature surrounding the administration of molecular and nanoparticle therapeutics, their pharmacokinetics, and contrasting mechanisms of action. The review aims to demonstrate the advancements in the field of conjugated nanomaterials and radiotherapeutics targeting, inhibiting, or bypassing the tumour microenvironment to promote further research that can improve treatment outcomes and toxicity rates.

Superparamagnetic Artificial Cells PLGA-Fe3O4 Micro/Nanocapsules for Cancer Targeted Delivery

Artificial cells have been extensively used in many fields, such as nanomedicine, biotherapy, blood substitutes, drug delivery, enzyme/gene therapy, cancer therapy, and the COVID-19 vaccine. The unique properties of superparamagnetic Fe3O4 nanoparticles have contributed to increased interest in using superparamagnetic artificial cells (PLGA-Fe3O4 micro/nanocapsules) for targeted therapy. In this review, the preparation methods of Fe3O4 NPs and superparamagnetic artificial cell PLGA-drug-Fe3O4 micro/nanocapsules are discussed. This review also focuses on the recent progress of superparamagnetic PLGA-drug-Fe3O4 micro/nanocapsules as targeted therapeutics. We shall concentrate on the use of superparamagnetic artificial cells in the form of PLGA-drug-Fe3O4 nanocapsules for magnetic hyperthermia/photothermal therapy and cancer therapies, including lung breast cancer and glioblastoma.

Lactosylated Chitosan Nanoparticles Potentiate the Anticancer Effects of Telmisartan In Vitro and in a N-Nitrosodiethylamine-Induced Mice Model of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related mortality worldwide. Telmisartan (TLM), a BSC class II drug, has been reported to have antiproliferative activity in HCC. However, its therapeutic activity is limited by poor bioavailability and unpredictable distribution. This work aimed to enhance TLM's liver uptake for HCC management through passive and active targeting pathways utilizing chitosan nanoparticles decorated with lactose (LCH NPs) as a delivery system. In vitro cell cytotoxicity and cellular uptake studies indicated that TLM-LCH NPs significantly (p < 0.05) enhanced the antiproliferative activity and cellular uptake percentage of TLM. In vivo bioavailability and liver biodistribution studies indicated that TLM-LCH NPs significantly (p < 0.05) enhanced TLM concentrations in plasma and the liver. The relative liver uptake of TLM from TLM-LCH NPs was 2-fold higher than that of unmodified NPs and 5-fold higher than that of plain TLM suspension. In vivo studies of a N-nitrosodiethylamine-induced HCC model revealed that administration of TLM through LCH NPs improved liver histology and resulted in lower serum alpha-fetoprotein (AFP), matrix metalloproteinase 2 (MMP-2), vascular endothelial growth factor (VEGF) levels, and liver weight index compared to plain TLM and TLM-loaded unmodified NPs. These results reflected the high potentiality of LCH NPs as a liver-targeted delivery system for TLM in the treatment of HCC.

Nanodelivery systems: An efficient and target-specific approach for drug-resistant cancers

BACKGROUND

Cancer treatment is still a global health challenge. Nowadays, chemotherapy is widely applied for treating cancer and reducing its burden. However, its application might be in accordance with various adverse effects by exposing the healthy tissues and multidrug resistance (MDR), leading to disease relapse or metastasis. In addition, due to tumor heterogeneity and the varied pharmacokinetic features of prescribed drugs, combination therapy has only shown modestly improved results in MDR malignancies. Nanotechnology has been explored as a potential tool for cancer treatment, due to the efficiency of nanoparticles to function as a vehicle for drug delivery.

METHODS

With this viewpoint, functionalized nanosystems have been investigated as a potential strategy to overcome drug resistance.

RESULTS

This approach aims to improve the efficacy of anticancer medicines while decreasing their associated side effects through a range of mechanisms, such as bypassing drug efflux, controlling drug release, and disrupting metabolism. This review discusses the MDR mechanisms contributing to therapeutic failure, the most cutting-edge approaches used in nanomedicine to create and assess nanocarriers, and designed nanomedicine to counteract MDR with emphasis on recent developments, their potential, and limitations.

CONCLUSIONS

Studies have shown that nanoparticle-mediated drug delivery confers distinct benefits over traditional pharmaceuticals, including improved biocompatibility, stability, permeability, retention effect, and targeting capabilities.

Nanomedicine in therapeutic warfront against estrogen receptor-positive breast cancer

Breast cancer (BC) is the most frequently diagnosed malignancy in women worldwide. Almost 70-80% of cases of BC are curable at the early non-metastatic stage. BC is a heterogeneous disease with different molecular subtypes. Around 70% of breast tumors exhibit estrogen-receptor (ER) expression and endocrine therapy is used for the treatment of these patients. However, there are high chances of recurrence in the endocrine therapy regimen. Though chemotherapy and radiation therapy have substantially improved survival rates and treatment outcomes in BC patients, there is an increased possibility of the development of resistance and dose-limiting toxicities. Conventional treatment approaches often suffer from low bioavailability, adverse effects due to the non-specific action of chemotherapeutics, and low antitumor efficacy. Nanomedicine has emerged as a conspicuous strategy for delivering anticancer therapeutics in BC management. It has revolutionized the area of cancer therapy by increasing the bioavailability of the therapeutics and improving their anticancer efficacy with reduced toxicities on healthy tissues. In this article, we have highlighted various mechanisms and pathways involved in the progression of ER-positive BC. Further, different nanocarriers delivering drugs, genes, and natural therapeutic agents for surmounting BC are the spotlights of this article.

Pharmacokinetics and tumor delivery of nanoparticles

Nanoparticles (NPs) have been widely used in different areas, including consumer products and medicine. In terms of biomedical applications, NPs or NP-based drug formulations have been extensively investigated for cancer diagnostics and therapy in preclinical studies, but the clinical translation rate is low. Therefore, a thorough and comprehensive understanding of the pharmacokinetics of NPs, especially in drug delivery efficiency to the target therapeutic tissue tumor, is important to design more effective nanomedicines and for proper assessment of the safety and risk of NPs. This review article focuses on the pharmacokinetics of both organic and inorganic NPs and their tumor delivery efficiencies, as well as the associated mechanisms involved. We discuss the absorption, distribution, metabolism, and excretion (ADME) processes following different routes of exposure and the mechanisms involved. Many physicochemical properties and experimental factors, including particle type, size, surface charge, zeta potential, surface coating, protein binding, dose, exposure route, species, cancer type, and tumor size can affect NP pharmacokinetics and tumor delivery efficiency. NPs can be absorbed with varying degrees following different exposure routes and mainly accumulate in liver and spleen, but also distribute to other tissues such as heart, lung, kidney and tumor tissues; and subsequently get metabolized and/or excreted mainly through hepatobiliary and renal elimination. Passive and active targeting strategies are the two major mechanisms of tumor delivery, while active targeting tends to have less toxicity and higher delivery efficiency through direct interaction between ligands and receptors. We also discuss challenges and perspectives remaining in the field of pharmacokinetics and tumor delivery efficiency of NPs.

Magnetic Iron Oxide Nanoparticles for Brain Imaging and Drug Delivery

Central nervous system (CNS) disorders affect as many as 1.5 billion people globally. The limited delivery of most imaging and therapeutic agents into the brain is a major challenge for treatment of CNS disorders. With the advent of nanotechnologies, controlled delivery of drugs with nanoparticles holds great promise in CNS disorders for overcoming the blood-brain barrier (BBB) and improving delivery efficacy. In recent years, magnetic iron oxide nanoparticles (MIONPs) have stood out as a promising theranostic nanoplatform for brain imaging and drug delivery as they possess unique physical properties and biodegradable characteristics. In this review, we summarize the recent advances in MIONP-based platforms as imaging and drug delivery agents for brain diseases. We firstly introduce the methods of synthesis and surface functionalization of MIONPs with emphasis on the inclusion of biocompatible polymers that allow for the addition of tailored physicochemical properties. We then discuss the recent advances in in vivo imaging and drug delivery applications using MIONPs. Finally, we present a perspective on the remaining challenges and possible future directions for MIONP-based brain delivery systems.

Tumor-Antigen Activated Dendritic Cell Membrane-Coated Biomimetic Nanoparticles with Orchestrating Immune Responses Promote Therapeutic Efficacy against Glioma

Immunotherapy has had a profound positive effect on certain types of cancer but has not improved the outcomes of glioma because of the blood-brain barrier (BBB) and immunosuppressive tumor microenvironment. In this study, we developed an activated mature dendritic cell membrane (aDCM)-coated nanoplatform, rapamycin (RAPA)-loaded poly(lactic-co-glycolic acid) (PLGA), named aDCM@PLGA/RAPA, which is a simple, efficient, and individualized strategy to cross the BBB and improve the immune microenvironment precisely. In vitro cells uptake and the transwell BBB model revealed that the aDCM@PLGA/RAPA can enhance homotypic-targeting and BBB-crossing efficiently. According to the in vitro and in vivo immune response efficacy of aDCM@PLGA/RAPA, the immature dendritic cells (DCs) could be stimulated into the matured status, which leads to further activation of immune cells, such as tumor-infiltrating T cells and natural killer cells, and can induce the subsequent immune responses through direct and indirect way. The aDCM@PLGA/RAPA treatment can not only inhibit glioma growth significantly but also has favorable potential ability to induce glial differentiation in the orthotopic glioma. Moreover, the aDCM@PLGA could induce a robust CD8⁺ effector and therefore suppress orthotopic glioma growth in a prophylactic setup, which indicates certain tumor immunity. Overall, our work provides an effective antiglioma drug delivery system which has great potential for tumor combination immunotherapy.

QbD-based fabrication of transferrin-anchored nanocarriers for targeted drug delivery to macrophages and colon cells for mucosal inflammation healing

Colon mucosal inflammation attracts a plethora of immune cells with overexpressed surface receptors. Colon drug targeting can be aided by exploiting overexpressed cell surface receptors which improve drug site retention for an extended period. We developed Tofacitinib citrate (Tofa) loaded transferrin anchored PLGA nanocarriers (Tofa-P/tfr NCs) via the quality by design (QbD) approach for specific binding to the transferrin receptor (TFR-1/CD71) overexpressed on macrophages and colon epithelial cells. Nanocarriers were produced using a modified emulsion-evaporation method with a protein adsorption technique. The QbD-risk assessment method was adopted to screen the variables impacting the quality of nanocarriers, which were then optimized using the 3³ Box-Behnken design of experiment (DOE). The obtained nanocarriers have the desired physicochemical properties, drug entrapment, tfr adsorption, stability, mucoadhesion, and sustained drug release pattern at pH 7.4 (colon pH). In vitro cell-based studies confirmed the cellular biocompatibility and considerable uptake of nanocarriers by colon and macrophage cells; the uptake was diminished by anti-CD71/TFR1 antibodies. Tofa-P/tfr NCs demonstrated good colon targeting potential in the dextran sulfate sodium (DSS) induced ulcerative colitis (UC) model. In vivo therapeutic efficacy against UC was established through restored morphological and histopathological scores, vascular integrity, antioxidant levels, hematological parameters, pro-inflammatory cytokine/marker levels, and microbial indices. Tofa-P/tfr NCs shut down the elevated STAT-1 and TFR-1 levels, demonstrating the enhanced efficacy of the encapsulated drug. Thus, the QbD-driven approach successfully developed Tofa-P/tfr NCs with good potential to mitigate mucosal inflammation by targeting colon and macrophage surface receptors.

Functional ligands for improving anticancer drug therapy: current status and applications to drug delivery systems

Conventional chemotherapy lacking target selectivity often leads to severe side effects, limiting the effectiveness of chemotherapy. Therefore, drug delivery systems ensuring both selective drug release and efficient intracellular uptake at the target sites are highly demanded in chemotherapy to improve the quality of life of patients with low toxicity. One of the effective approaches for tumor-selective drug delivery is the adoption of functional ligands that can interact with specific receptors overexpressed in malignant cancer cells. Various functional ligands including folic acid, hyaluronic acid, transferrin, peptides, and antibodies, have been extensively explored to develop tumor-selective drug delivery systems. Furthermore, cell-penetrating peptides or ligands for tight junction opening are also actively pursued to improve the intracellular trafficking of anticancer drugs. Sometimes, multiple ligands with different roles are used in combination to enhance the cellular uptake as well as target selectivity of anticancer drugs. In this review, the current status of various functional ligands applicable to improve the effectiveness of cancer chemotherapy is overviewed with a focus on their roles, characteristics, and preclinical/clinical applications.

A Review of Multifunction Smart Nanoparticle based Drug Delivery Systems

Cancer nano-therapeutics are rapidly evolving and are often used to overcome a number of concerns with traditional drug delivery methods, including non-specific drug targeting and distribution, low oral bioavailability, and poor hydrophilicity. Modern nano-based targeting techniques have been developed as a result of advances in nano vehicle engineering and materials science, which may bring people with cancer a new hope. Clinical trials have been authorized for a number of medicinal nanocarriers. Nanocarriers with the best feasible size and surface attributes have been developed to optimize biodistribution and increase blood circulation duration. Nanotherapeutics can carry preloaded active medicine towards cancerous cells by preferentially leveraging the specific physiopathology of malignancies. In contrast to passive targeting, active targeting strategies involving antigens or ligands, developed against specific tumor sites, boost the selectivity of these curative nanovehicles. Another barrier that nanoparticles may resolve or lessen is drug resistance. Multifunctional and complex nanoparticles are currently being explored and are predicted to usher in a new era of nanoparticles that will allow for more individualized and customized cancer therapy. The potential prospects and opportunities of stimuli-triggered nanosystems in therapeutic trials are also explored in this review.

Engineering nanosystems to overcome barriers to cancer diagnosis and treatment

Over the past two decades, multidisciplinary investigations into the development of nanoparticles for medical applications have continually increased. However, nanoparticles are still subject to biological barriers and biodistribution challenges, which limit their overall clinical potential. This has motivated the implementation of innovational modifications to a range of nanoparticle formulations designed for cancer imaging and/or cancer treatment to overcome specific barriers and shift the accumulation of payloads toward the diseased tissues. In recent years, novel technological and chemical approaches have been employed to modify or functionalize the surface of nanoparticles or manipulate the characteristics of nanoparticles. Combining these approaches with the identification of critical biomarkers provides new strategies for enhancing nanoparticle specificity for both cancer diagnostic and therapeutic applications. This review discusses the most recent advances in the design and engineering of nanoparticles as well as future directions for developing the next generation of nanomedicines.

Engineered Magnetic Polymer Nanoparticles Can Ameliorate Breast Cancer Treatment Inducing Pyroptosis-Starvation along with Chemotherapy

Nanotechnology has shown a revolution in cancer treatments, including breast cancers. However, there remain some challenges and translational hurdles. Surgery, radiotherapy, and chemotherapy are the primary treatment methods for breast cancer, although drug combinations showed promising results in preclinical studies. Herein we report the development of a smart drug delivery system (DDS) to efficiently treat breast cancer by pyroptosis-starvation-chemotherapeutic combination. Cancer-starvation agent glucose oxidase was chemically attached to synthesized iron oxide nanoparticles which were entrapped inside poly(lactic-co-glycolic acid) along with apoptosis-associated speck-like protein containing a caspase recruitment domain plasmid and paclitaxel (PTX). An emulsion solvent evaporation method was used to prepare the DDS. The surface of the DDS was modified with chitosan to which aptamer was attached to achieve site-specific targeting. Hence, the prepared DDS could be targeted to a tumor site by both external magnet and aptamer to obtain an enhanced accumulation of drugs at the tumor site. The final size of the aptamer-decorated DDS was less than 200 nm, and the encapsulation efficiency of PTX was 76.5 ± 2.5%. Drug release from the developed DDS was much higher at pH 5.5 than at pH 7.4, ensuring the pH sensitivity of the DDS. Due to efficient dual targeting of the DDS, in vitro viability of 4T1 cells was reduced to 12.1 ± 1.6%, whereas the nontargeted group and free PTX group could reduce the viability of cells to 29.2 ± 2.4 and 46.2 ± 1.6%, respectively. Our DDS showed a synergistic effect in vitro and no severe side effects in vivo. This DDS has strong potential to treat various cancers.

Alpha-fetoprotein mediated targeting of polymeric nanoparticles to treat solid tumors

Background: Serious side effects caused by paclitaxel formulation, containing toxic solubilizer Cremophor^® EL, and its nonspecific accumulation greatly limit clinical paclitaxel application. Aim: To design paclitaxel-loaded copolymer of lactic and glycolic acids nanoparticles decorated with alpha-fetoprotein third domain (rAFP3d-NP) to increase paclitaxel safety profile. Methods: rAFP3d-NP was obtained via carbodiimide technique. Results: The particles were characterized with high paclitaxel loading content of 5% and size of 280 nm. rAFP3d-NP revealed biphasic profile with 67% release of paclitaxel during 220 h. Increased area under the curve_inf and mean residence time values after rAFP3d-NP administration confirmed prolonged blood circulation compared with paclitaxel. rAFP3d-NP demonstrated significant tumor growth inhibition at 4T1 and SKOV-3 models. Conclusion: rAFP3d-NP is a promising delivery system for paclitaxel and can be applied similarly for delivery of other hydrophobic drugs.

Computational methodology for drug delivery to the inner ear using magnetic nanoparticle aggregates

BACKGROUND AND OBJECTIVE

The main goal of the proposed study is to improve the efficiency of the ear treatment via targeted drug delivery to the inner ear, i.e. the cochlea. Although pharmacotherapy has been proposed as a solution to prevent damage or restore functionality to hair cells, the main challenge in such treatments is ensuring adequate drug delivery to the cells. To this end, we present a methodology for the evaluation of the magnetic forces needed to move magnetic particle nanorobots (abbreviated as MNP) and their aggregates through the cochlea round window membrane (RWM).

METHODS

The FEM - Lagrangian-Eulerian approach (Abaqus software) was used to determine the specific parameters of movement of the nanoparticles crossing the RWM. This method results in a high consistency of FEM simulations and in-vivo experimental results in regards to the required magnetic force during the movement of spherical nanoparticles with a given viscosity η_ave. Based on the analysis of the experimental studies found in subject literature, the sizes of the MNPs and their aggregates able to cross RWM with and without the application of magnetic force F_M have been determined.

RESULTS

The present work accounts for both the experimental and theoretical aspects of these investigations. Presented research confirms the definite usability of the Lagrange-Euler method for the precise determination of the required magnetic force value FM to control the accelerated motion of MNP aggregates of complex shapes through RWM. It is possible to determine the predominant parameters with a precision of less than 5% for single-layer aggregates and spatial aggregates crossing the RWM. It can be concluded that the MNPs and their aggregates should not be larger than 500-750 nm to cross the RWM with high velocities of penetration close to 800 nm/s for magnetic forces of hundreds 10^-14 Newtons.

CONCLUSIONS

The proposed Lagrangian-Eulerian approach is capable of accurately predicting the movement parameters of MNP aggregates of irregular shape that are close to the experimental test cases. The presented method can serve as a supplementary tool for the design of drug delivery systems to the inner ear using MNPs.

Nano-strategies as Oral Drug Delivery Platforms for Treatment of Cancer: Challenges and Future Perspectives

Oral drug administration is the oldest and widely used method for drug administration. The objectives behind developing an oral drug delivery for the treatment of cancer are to achieve low cost treatment by utilizing novel techniques to target cancer through gut-associated lymphoid tissue (GALT) and to enhance patient comfort and compliance through a hospital-free treatment leading to "Chemotherapy at Home." Unfortunately, due to the physiological environment of the GIT and physicochemical properties of drug candidate, the efficacy of oral drug delivery methods is limited in the treatment of cancer. Due to their low hydrophilicity, high P-gp efflux and restricted intestinal permeability most of the anti-cancer drugs fail to achieve oral bioavailability. The review focuses on the efforts, challenges, opportunities and studies conducted by scientists worldwide on the oral administration of anticancer medications via nanocarriers such as liposomes, SLNs and dendrimers, because of their potential to overcome the epithelial barrier associated with GALT, as well as the applications of different polymers in targeting the cancer. The oral delivery can set newer horizons in cancer therapy to make it more patient friendly.

Development and evaluation of core-shell nanocarrier system for enhancing the cytotoxicity of doxorubicin/ metformin combination against breast cancer cell line

Breast cancer is the most invasive and life-threatening cancer in women. The treatment options are usually a combination of mastectomy, radiation therapy, hormonal therapy and chemotherapy. As a standard practice, doxorubicin (DOX) is one of the commonly used drugs for breast cancer treatment. However, DOX is known to have many harmful adverse effects including its cardiotoxicity. Hence, recent reports used metformin (MET), an anti-diabetic drug, as an adjuvant therapy to decrease the severity of DOX's adverse effects and to improve its ultimate therapeutic outcome. The current study is aimed at co-loading and enhancing the encapsulation efficiency of the hydrophilic DOX and MET in poly(lactic-co-glycolic acid) (PLGA) nanocapsules (NCs) with oil core for breast cancer treatment. The NCs were developed by single emulsification-solvent diffusion technique, and were optimized through using two types of oils, pluronics and PLGA (50:50) of different molecular weights followed by various physicochemical characterizations. The obtained DOX/MET-loaded NCs showed the size and polydispersity index (PDI) of 203.0 ± 3.4 nm and 0.081 ± 0.03, respectively with a surface charge of -2.15 ± 0.2 mV. The entrapment efficiency of DOX and MET were about 93.7% ± 2.9 and 70% ± 1.6, respectively. The developed PLGA core-shell NCs successfully sustained the DOX/MET release for more than 30 days. The in-vitro results showed a significant enhancement in DOX cytotoxic effect as well as a duplication in its apoptotic effect upon addition of MET for both free DOX/MET combination and DOX/MET-loaded PLGA NCs against MCF-7. Besides, flow cytometry demonstrated that the DOX/MET-loaded NCs possess their antitumor effect by preventing DNA replication and cell division. This study provides a promising facile, rapid and reproducible single emulsification-solvent diffusion technique for improving the encapsulation and release of hydrophilic drugs in nanocapsules for 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.

Recent Progress in Nanostructured Smart Drug Delivery Systems for Cancer Therapy: A Review

Traditional treatment approaches for cancer involve intravenous chemotherapy or other forms of drug delivery. These therapeutic measures suffer from several limitations such as nonspecific targeting, poor biodistribution, and buildup of drug resistances. However, significant technological advancements have been made in terms of superior modes of drug delivery over the last few decades. Technical capability in analyzing the molecular mechanisms of tumor biology, nanotechnology─particularly the development of biocompatible nanoparticles, surface modification techniques, microelectronics, and material sciences─has increased. As a result, a significant number of nanostructured carriers that can deliver drugs to specific cancerous sites with high efficiency have been developed. This particular maneuver that enables the introduction of a therapeutic nanostructured substance in the body by controlling the rate, time, and place is defined as the nanostructured drug delivery system (NDDS). Because of their versatility and ability to incorporate features such as specific targeting, water solubility, stability, biocompatibility, degradability, and ability to reverse drug resistance, they have attracted the interest of the scientific community, in general, and nanotechnologists as well as biomedical scientists. To keep pace with the rapid advancement of nanotechnology, specific technical aspects of the recent NDDSs and their prospects need to be reported coherently. To address these ongoing issues, this review article provides an overview of different NDDSs such as lipids, polymers, and inorganic nanoparticles. In addition, this review also reports the challenges of current NDDSs and points out the prospective research directions of these nanocarriers. From our focused review, we conclude that still now the most advanced and potent field of application for NDDSs is lipid-based, while other significantly potential fields include polymer-based and inorganic NDDSs. However, despite the promises, challenges remain in practical implementations of such NDDSs in terms of dosage and stability, and caution should be exercised regarding biocompatibility of materials. Considering these aspects objectively, this review on NDDSs will be particularly of interest for small-to-large scale industrial researchers and academicians with expertise in drug delivery, cancer research, and nanotechnology.

Recent Advances in the Surface Functionalization of PLGA-Based Nanomedicines

Therapeutics are habitually characterized by short plasma half-lives and little affinity for targeted cells. To overcome these challenges, nanoparticulate systems have entered into the disease arena. Poly(d,l-lactide-co-glycolide) (PLGA) is one of the most relevant biocompatible materials to construct drug nanocarriers. Understanding the physical chemistry of this copolymer and current knowledge of its biological fate will help in engineering efficient PLGA-based nanomedicines. Surface modification of the nanoparticle structure has been proposed as a required functionalization to optimize the performance in biological systems and to localize the PLGA colloid into the site of action. In this review, a background is provided on the properties and biodegradation of the copolymer. Methods to formulate PLGA nanoparticles, as well as their in vitro performance and in vivo fate, are briefly discussed. In addition, a special focus is placed on the analysis of current research in the use of surface modification strategies to engineer PLGA nanoparticles, i.e., PEGylation and the use of PEG alternatives, surfactants and lipids to improve in vitro and in vivo stability and to create hydrophilic shells or stealth protection for the nanoparticle. Finally, an update on the use of ligands to decorate the surface of PLGA nanomedicines is included in the review.

Polymeric Nanoparticles: Exploring the Current Drug Development and Therapeutic Insight of Breast Cancer Treatment and Recommendations

This manuscript aims to provide the latest update on polymeric nanoparticle drug delivery system for breast cancer treatment after 2015 and how research-oriented it is based on the available research data. Therefore, the authors have chosen breast cancer which is the most frequent and common reason for mortality in women worldwide. The first-line treatment for breast cancer treatment is chemotherapy, apart from surgery, radiation and hormonal therapy. Chemotherapy is associated with lesser therapeutics and undesirable side effects and hence. In addition, drug resistance affects the therapeutic dose to the target site. Although various nano-based formulations have been developed for effective treatment, the polymeric nanoparticles effectively avoid the lacunae of conventional chemotherapy. There has been an effort made to understand the chemotherapy drugs and their conventional formulation-related problems for better targeting and effective drug delivery for breast cancer treatment. Thus, the polymeric nanoparticles as a strategy overcome the associated problems with resulting dose reduction, enhanced bioavailability, reduced side effects, etc. This present review has compiled the research reports published from 2015 to 2021 from different databases, such as PubMed, Google Scholar, ScienceDirect, which are related to breast cancer treatment in which the drug delivery of numerous chemotherapeutic agents alone or in combination, including phytoconstituents formulated into various polymer-based nanoparticles.

Development, Characterization, and Evaluation of α-Mangostin-Loaded Polymeric Nanoparticle Gel for Topical Therapy in Skin Cancer

The aim of this study was to prepare and evaluate α-mangostin-loaded polymeric nanoparticle gel (α-MNG-PLGA) formulation to enhance α-mangostin delivery in an epidermal carcinoma. The poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were developed using the emulsion-diffusion-evaporation technique with a 3-level 3-factor Box-Behnken design. The NPs were characterized and evaluated for particle size distribution, zeta potential (mV), drug release, and skin permeation. The formulated PLGA NPs were converted into a preformed carbopol gel base and were further evaluated for texture analysis, the cytotoxic effect of PLGA NPs against B16-F10 melanoma cells, and in vitro radical scavenging activity. The nanoscale particles were spherical, consistent, and average in size (168.06 ± 17.02 nm), with an entrapment efficiency (EE) of 84.26 ± 8.23% and a zeta potential of -25.3 ± 7.1 mV. Their drug release percentages in phosphate-buffered solution (PBS) at pH 7.4 and pH 6.5 were 87.07 ± 6.95% and 89.50 ± 9.50%, respectively. The release of α-MNG from NPs in vitro demonstrated that the biphasic release system, namely, immediate release in the initial phase, was accompanied by sustained drug release. The texture study of the developed α-MNG-PLGA NPs gel revealed its characteristics, including viscosity, hardness, consistency, and cohesiveness. The drug flux from α-MNG-PLGA NPs gel and α-MNG gel was 79.32 ± 7.91 and 16.88 ± 7.18 µg/cm2/h in 24 h, respectively. The confocal study showed that α-MNG-PLGA NPs penetrated up to 230.02 µm deep into the skin layer compared to 15.21 µm by dye solution. MTT assay and radical scavenging potential indicated that α-MNG-PLGA NPs gel had a significant cytotoxic effect and antioxidant effect compared to α-MNG gel (p < 0.05). Thus, using the developed α-MNG-PLGA in treating skin cancer could be a promising approach.

Pharmaceutical Aspects of Nanocarriers for Smart Anticancer Therapy

Drug delivery to tumor sites using nanotechnology has been demonstrated to overcome the drawbacks of conventional anticancer drugs. Altering the surface shape and geometry of nanocomposites alters their chemical properties, which can confer multiple attributes to nanocarriers for the treatment of cancer and their use as imaging agents for cancer diagnosis. However, heterogeneity and blood flow in human cancer limit the distribution of nanoparticles at the site of tumor tisues. For targeted delivery and controlled release of drug molecules in harsh tumor microenvironments, smart nanocarriers combined with various stimuli-responsive materials have been developed. In this review, we describe nanomaterials for smart anticancer therapy as well as their pharmaceutical aspects including pharmaceutical process, formulation, controlled drug release, drug targetability, and pharmacokinetic or pharmacodynamic profiles of smart nanocarriers. Inorganic or organic-inorganic hybrid nanoplatforms and the electrospinning process have also been briefly described here.

Intracellular delivery of anti-BCR/ABL antibody by PLGA nanoparticles suppresses the oncogenesis of chronic myeloid leukemia cells

BACKGROUND

The pathogenesis of chronic myeloid leukemia (CML) is the formation of the BCR/ABL protein, which is encoded by the bcr/abl fusion gene, possessing abnormal tyrosine kinase activity. Despite the wide application of tyrosine kinase inhibitors (TKIs) in CML treatment, TKIs drug resistance or intolerance limits their further usage in a subset of patients. Furthermore, TKIs inhibit the tyrosine kinase activity of the BCR/ABL oncoprotein while failing to eliminate the pathologenic oncoprotein. To develop alternative strategies for CML treatment using therapeutic antibodies, and to address the issue that antibodies cannot pass through cell membranes, we have established a novel intracellular delivery of anti-BCR/ABL antibodies, which serves as a prerequisite for CML therapy.

METHODS

Anti-BCR/ABL antibodies were encapsulated in poly(D, L-lactide-co-glycolide) nanoparticles (PLGA NPs) by a double emulsion method, and transferrin was labeled on the surface of the nanoparticles (Ab@Tf-Cou6-PLGA NPs). The characteristics of nanoparticles were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Cellular uptake of nanoparticles was measured by flow cytometry (FCM). The effect of nanoparticles on the apoptosis and proliferation of CML cells was testified by FCM and CCK-8 assay. In addition, the anti-cancer impact of nanoparticles was evaluated in mouse models of CML.

RESULTS

The results demonstrated that the Ab@Tf-Cou6-PLGA NPs functioned as an intracellular deliverer of antibodies, and exhibited an excellent effect on degrading BCR/ABL oncoprotein in CML cells via the Trim-Away pathway. Treatment with Ab@Tf-Cou6-PLGA NPs inhibited the proliferation and induced the apoptosis of CML cells in vitro as well as impaired the oncogenesis ability of CML cells in vivo.

CONCLUSIONS

In conclusion, our study indicated that this approach achieved safe and efficient intracellular delivery of antibodies and degraded BCR/ABL oncoprotein via the Trim-Away pathway, which provides a promising therapeutic strategy for CML patients, particularly those with TKI resistance.

Dual targeting smart drug delivery system for multimodal synergistic combination cancer therapy with reduced cardiotoxicity

This study first reports the development of a smart drug delivery system (DDS) for multimodal synergistic cancer therapy combining chemo-photothermal-starvation approaches. A magnetic photothermal agent was synthesized by preparing iron oxide (IO) nanoparticles (NPs) with covalently attached indocyanine green (ICG) and glucose oxidase (GOx) (ICGOx@IO). Synthesized ICGOx@IO NPs were co-encapsulated with doxorubicin (Dox) and EGCG ((-)-epigallocatechin-3-gallate) inside PLGA (poly(lactic-co-glycolic acid)) NPs using multiple emulsion solvent evaporation method. Such formulation gave the advantage of triggered drug release by near-infrared (NIR) laser irradiation (808 nm at 1 W/cm²). RGD peptide was attached to the surface of PLGA NPs and the final hydrodynamic size was around 210 nm. Dual targeting by peptide and 240 mT external magnet significantly improved cellular uptake. Cellular uptake was observed using FACS, electron and optical microscopy. Dual targeting along with laser irradiation could reduce in vitro cell viability by 90 ± 2% (Dox-equivalent dose: 10 µg/ml) and complete tumor ablation was achieved in vivo due to synergetic therapeutic effect. Another attractive feature of the DDS was the significant reduction of cardiotoxicity of doxorubicin by EGCG. This new platform is thus expected to hold strong promise for future multimodal combination therapy of cancers. STATEMENT OF SIGNIFICANCE: Doxorubicin is one of the most studied and effective chemotherapeutic agents whose application is hindered due to its cardiotoxicity. In this study, we used (-)-Epigallocatechin-3-gallate (EGCG) to overcome that limitation. However, drug delivery to tumor sites with no/minimum accumulation in healthy organs is always challenging. Although peptide-based targeting is very popular, the effectiveness of receptor/ligand binding active targeting is sometimes questioned which motivated us to apply dual targeting approach. Multimodal therapies can exhibit synergistic effects and subsequently reduce the required dose of drug over monotherapy. We aimed to achieve chemo-photothermal-starvation combination therapy in this study and such achievement is yet to be reported. Our developed system also has the advantage of triggered drug release by near-infrared (NIR) laser irradiation.

A Tri-Stimuli Responsive (Maghemite/PLGA)/Chitosan Nanostructure with Promising Applications in Lung Cancer

A (core/shell)/shell nanostructure (production performance ≈ 50%, mean diameter ≈ 330 nm) was built using maghemite, PLGA, and chitosan. An extensive characterization proved the complete inclusion of the maghemite nuclei into the PLGA matrix (by nanoprecipitation solvent evaporation) and the disposition of the chitosan shell onto the nanocomposite (by coacervation). Short-term stability and the adequate magnetism of the nanocomposites were demonstrated by size and electrokinetic determinations, and by defining the first magnetization curve and the responsiveness of the colloid to a permanent magnet, respectively. Safety of the nanoparticles was postulated when considering the results from blood compatibility studies, and toxicity assays against human colonic CCD-18 fibroblasts and colon carcinoma T-84 cells. Cisplatin incorporation to the PLGA matrix generated appropriate loading values (≈15%), and a dual pH- and heat (hyperthermia)-responsive drug release behaviour (≈4.7-fold faster release at pH 5.0 and 45 °C compared to pH 7.4 and 37 °C). The half maximal inhibitory concentration of the cisplatin-loaded nanoparticles against human lung adenocarcinoma A-549 cells was ≈1.6-fold less than that of the free chemotherapeutic. Such a biocompatible and tri-stimuli responsive (maghemite/PLGA)/chitosan nanostructure may found a promising use for the effective treatment of lung cancer.

Transferrin: Biology and Use in Receptor-Targeted Nanotherapy of Gliomas

Gliomas constitute 80% of malignant brain tumors. The survival rate of patients diagnosed with malignant gliomas is only 34.4%, as seen in both adults as well as children. The biggest challenge in treatment of gliomas is the impenetrable blood-brain barrier. With the availability of only a very few choices of chemotherapeutics in the treatment of gliomas, it is imperative that a novel strategy to effectively deliver drugs into the brain is researched and applied. The most popular strategy that is gaining importance is the receptor-mediated uptake of targeted nanoparticles comprising of ligands specific to the receptors. This review discusses briefly one such receptor called the transferrin receptor that is highly expressed in the brain and can be applied effectively for targeted nanoparticle delivery systems in gliomas.

Magnetic-core-based silibinin nanopolymeric carriers for the treatment of renal cell cancer

AIMS

Silibinin offers potential anticancer effect with less aqueous solubility and high permeability. The present study aimed to develop biocompatible magnetic-core-based nanopolymeric carriers of poly (D, l-lactide-co-glycolic) acid (PLGA) encapsulated silibinin for the sustained release action on renal cancerous cell.

MAIN METHODS

The synthesized iron oxide nanoparticles were prepared by precipitation method via encapsulation of silibinin in PLGA network using double emulsion method. The nanoparticle formulations were characterized for morphological, physicochemical properties (HRTEM, FTIR, Raman Spectroscopy and VSM), in vitro drug release and cytotoxicity study on kidney cancer cells (A-498). The safety of magnetic-core-based silibinin nanopolymeric carriers was conducted by i.v. administration at a dose of 50 mg/kg in mice.

KEY FINDINGS

The mean particle size, zeta potential and % encapsulation efficiency of magnetic-core-based silibinin nanopolymeric carriers were found to be 285.9 ± 0.28 nm, -14.71 ± 0.15 mV and 84.76 ± 1.29%, respectively. The saturation magnetization of magnetic core and optimized nanoparticles were reported as 36.35 emu/g and 12.78 emu/g, respectively. HRTEM analyses revealed the spherical shapes of the particles with uniform size distribution. The in vitro release profile of silibinin from the nanoparticles exhibited a sustained delivery for 15 days and displayed better cytotoxicity against human kidney cancer cells (A-498) than silibinin. In vivo study showed the safety of magnetic-core-based silibinin nanopolymeric carriers in mice.

SIGNIFICANCE

The magnetic-core-based silibinin nanopolymeric carriers will act as a potential carrier for targeted transportation of actives in cancer therapy.

Increasing Brain Permeability of PHA-767491, a Cell Division Cycle 7 Kinase Inhibitor, with Biodegradable Polymeric Nanoparticles

A potent cell division cycle 7 (CDC7) kinase inhibitor, known as PHA-767491, has been described to reduce the transactive response DNA binding protein of 43 KDa (TDP-43) phosphorylation in vitro and in vivo, which is one of the main proteins found to aggregate and accumulate in the cytoplasm of motoneurons in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients. However, the main drawback of this compound is its low permeability to the central nervous system (CNS), limiting its use for the treatment of neurological conditions. In this context, the use of drug delivery systems like nanocarriers has become an interesting approach to improve drug release to the CNS. In this study, we prepared and characterized biodegradable nanoparticles in order to encapsulate PHA-767491 and improve its permeability to the CNS. Our results demonstrate that poly (lactic-co-glycolic acid) (PLGA) nanoparticles with an average radius between 145 and 155 nm could be used to entrap PHA-767491 and enhance the permeability of this compound through the blood–brain barrier (BBB), becoming a promising candidate for the treatment of TDP-43 proteinopathies such as ALS.

Engineering of stealth (maghemite/PLGA)/chitosan (core/shell)/shell nanocomposites with potential applications for combined MRI and hyperthermia against cancer

(Maghemite/poly(d,l-lactide-co-glycolide))/chitosan (core/shell)/shell nanoparticles have been prepared reproducibly by nanoprecipitation solvent evaporation plus coacervation (production performance ≈ 45%, average size ≈ 325 nm). Transmission electron microscopy, energy dispersive X-ray spectroscopy, electrophoretic determinations, and X-ray diffraction patterns demonstrated the satisfactory embedment of iron oxide nanocores within the solid polymer matrix and the formation of an external shell of chitosan in the nanostructure. The adequate magnetic responsiveness of the nanocomposites was characterized in vitro by hysteresis cycle determinations and by visualization of the nanosystem under the influence of a 0.4 T permanent magnet. Safety and biocompatibility of the (core/shell)/shell particles were based on in vitro haemocompatibility studies and cytotoxicity tests against HFF-1 human foreskin fibroblasts and on ex vivo toxicity assessments on tissue samples from Balb/c mice. Transversal relaxivities, determined in vitro at a low magnetic field of 1.44 T, demonstrated their capability as T2 contrast agents for magnetic resonance imaging, being comparable to that of some iron oxide-based contrast agents. Heating properties were evaluated in a high frequency alternating electromagnetic gradient: a constant maximum temperature of ≈46 °C was generated within ≈50 min, while antitumour hyperthermia tests on T-84 colonic adenocarcinoma cells proved the relevant decrease in cell viability (to ≈ 39%) when treated with the nanosystem under the influence of that electromagnetic field. Finally, in vivo magnetic resonance imaging studies and ex vivo histology determinations of iron deposits postulated the efficacy of chitosan to provide long-circulating capabilities to the nanocomposites, retarding nanoparticle recognition by the mononuclear phagocyte system. To our knowledge, this is the first study describing such a type of biocompatible and long-circulating nanoplatform with promising theranostic applications (biomedical imaging and hyperthermia) against cancer.

Nanoparticle-Based Drug Delivery in Cancer Therapy and Its Role in Overcoming Drug Resistance

Nanotechnology has been extensively studied and exploited for cancer treatment as nanoparticles can play a significant role as a drug delivery system. Compared to conventional drugs, nanoparticle-based drug delivery has specific advantages, such as improved stability and biocompatibility, enhanced permeability and retention effect, and precise targeting. The application and development of hybrid nanoparticles, which incorporates the combined properties of different nanoparticles, has led this type of drug-carrier system to the next level. In addition, nanoparticle-based drug delivery systems have been shown to play a role in overcoming cancer-related drug resistance. The mechanisms of cancer drug resistance include overexpression of drug efflux transporters, defective apoptotic pathways, and hypoxic environment. Nanoparticles targeting these mechanisms can lead to an improvement in the reversal of multidrug resistance. Furthermore, as more tumor drug resistance mechanisms are revealed, nanoparticles are increasingly being developed to target these mechanisms. Moreover, scientists have recently started to investigate the role of nanoparticles in immunotherapy, which plays a more important role in cancer treatment. In this review, we discuss the roles of nanoparticles and hybrid nanoparticles for drug delivery in chemotherapy, targeted therapy, and immunotherapy and describe the targeting mechanism of nanoparticle-based drug delivery as well as its function on reversing drug resistance.

Nanoparticle-Based Drug Delivery in Cancer Therapy and Its Role in Overcoming Drug Resistance

Nanotechnology has been extensively studied and exploited for cancer treatment as nanoparticles can play a significant role as a drug delivery system. Compared to conventional drugs, nanoparticle-based drug delivery has specific advantages, such as improved stability and biocompatibility, enhanced permeability and retention effect, and precise targeting. The application and development of hybrid nanoparticles, which incorporates the combined properties of different nanoparticles, has led this type of drug-carrier system to the next level. In addition, nanoparticle-based drug delivery systems have been shown to play a role in overcoming cancer-related drug resistance. The mechanisms of cancer drug resistance include overexpression of drug efflux transporters, defective apoptotic pathways, and hypoxic environment. Nanoparticles targeting these mechanisms can lead to an improvement in the reversal of multidrug resistance. Furthermore, as more tumor drug resistance mechanisms are revealed, nanoparticles are increasingly being developed to target these mechanisms. Moreover, scientists have recently started to investigate the role of nanoparticles in immunotherapy, which plays a more important role in cancer treatment. In this review, we discuss the roles of nanoparticles and hybrid nanoparticles for drug delivery in chemotherapy, targeted therapy, and immunotherapy and describe the targeting mechanism of nanoparticle-based drug delivery as well as its function on reversing drug resistance.

Recognition Sites for Cancer-targeting Drug Delivery Systems

BACKGROUND

Target-homing drug delivery systems are now gaining significant attention for use as novel therapeutic approaches in antitumor targeting for cancer therapy. Numerous targeted drug delivery systems have been designed to improve the targeting effects because these systems can display a range of favorable properties, thus, providing suitable characteristics for clinical applicability of anticancer drugs, such as increasing the solubility, and improving the drug distribution at target sites. The majority of these targeting systems are designed with respect to differences between cancerous and normal tissues, for instance, the low pH of tumor tissues or overexpressed receptors on tumor cell membranes. Due to the growing number of targeting possibilities, it is important to know the tumor-specific recognition strategies for designing novel, targeted, drug delivery systems. Herein, we identify and summarize literature pertaining to various recognition sites for optimizing the design of targeted drug delivery systems to augment current chemotherapeutic approaches.

OBJECTIVE

This review focuses on the identification of the recognition sites for developing targeted drug delivery systems for use in cancer therapeutics.

METHODS

We have reviewed and compiled cancer-specific recognition sites and their abnormal characteristics within tumor tissues (low pH, high glutathione, targetable receptors, etc.), tumor cells (receptor overexpression or tumor cell membrane changes) and tumor cell organelles (nuclear and endoplasmic reticular dysregulation) utilizing existing scientific literature. Moreover, we have highlighted the design of some targeted drug delivery systems that can be used as homing tools for these recognition sites.

RESULTS AND CONCLUSION

Targeted drug delivery systems are a promising therapeutic approach for tumor chemotherapy. Additional research focused on finding novel recognition sites, and subsequent development of targeting moieties for use with drug delivery systems will aid in the evaluation and clinical application of new and improved chemotherapeutics.

Nanotechnology-Based Biopolymeric Oral Delivery Platforms for Advanced Cancer Treatment

Routes of drug administration and their corresponding physiochemical characteristics play major roles in drug therapeutic efficiency and biological effects. Each route of delivery has favourable aspects and limitations. The oral route of delivery is the most convenient, widely accepted and safe route. However, the oral route of chemotherapeutics to date have displayed high gastric degradation, low aqueous solubility, poor formulation stability and minimum intestinal absorption. Thus, mainstream anti-cancer drugs in current formulations are not suitable as oral chemotherapeutic formulations. The use of biopolymers such as chitosan, gelatin, hyaluronic acid and polyglutamic acid, for the synthesis of oral delivery platforms, have potential to help overcome problems associated with oral delivery of chemotherapeutics. Biopolymers have favourable stimuli-responsive properties, and thus can be used to improve oral bioavailability of anti-cancer drugs. These biopolymeric formulations can protect gastric-sensitive drugs from pH degradation, target specific binding sites for targeted absorption and consequently control drug release. In this review, the use of various biopolymers as oral drug delivery systems for chemotherapeutics will be discussed.

Recent Advances in Magnetite Nanoparticle Functionalization for Nanomedicine

Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe3O4) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated in clinical practice. This article makes a summary of the surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine.

Transferrin-Conjugated Docetaxel-PLGA Nanoparticles for Tumor Targeting: Influence on MCF-7 Cell Cycle

Targeted drug delivery systems are commonly used to improve the therapeutic index of anti-cancer drugs by increasing their selectivity and reducing systemic distribution and toxicity. Ligand-conjugated nanoparticles (NPs) can be effectively applied for active chemotherapeutic targeting to overexpressed receptors of tumor cells. In this study, transferrin (Tf) was successfully conjugated with poly-l-lactic-co-glycolic acid (PLGA) using ethylene diamine confirmed by NMR, for the loading of docetaxel trihydrate (DCT) into PLGA nanoparticles (NPs). The DCT-loaded Tf-conjugated PLGA NPs were produced by an emulsion-solvent evaporation technique, and a 3² full factorial design was used to optimize the nanoparticle formulations. The DCT-loaded Tf-conjugated PLGA NPs were characterized by FTIR spectroscopy, differential scanning calorimetry, powder X-ray diffraction (PXRD), TEM, particle size, and zeta potential analysis. In vitro release kinetics confirmed that release of DCT from the designed formulations followed a zero-order kinetics and a diffusion controlled non-Fickian release profile. The DCT-loaded Tf-conjugated PLGA NPs were evaluated in vitro in MCF-7 cells for bioactivity assessment. Cytotoxicity studies confirmed that the Tf-conjugated PLGA NPs were more active than the non-conjugated counterparts. Cell uptake studies re-confirmed the ligand-mediated active targeting of the formulated NPs. From the cell cycle analysis, the anti-cancer activity of DCT-loaded Tf-conjugated PLGA NPs was shown to occur by arresting the G₂/M phase.

Nanomagnetite-embedded PLGA Spheres for Multipurpose Medical Applications

We report on the synthesis and evaluation of biopolymeric spheres of poly(lactide-co-glycolide) containing different amounts of magnetite nanoparticles and Ibuprofen (PLGA-Fe₃O₄-IBUP), but also chitosan (PLGA-CS-Fe₃O₄-IBUP), to be considered as drug delivery systems. Besides morphological, structural, and compositional characterizations, the PLGA-Fe₃O₄-IBUP composite microspheres were subjected to drug release studies, performed both under biomimetically-simulated dynamic conditions and under external radiofrequency magnetic fields. The experimental data resulted by performing the drug release studies evidenced that PLGA-Fe₃O₄-IBUP microspheres with the lowest contents of Fe₃O₄ nanoparticles are optimal candidates for triggered drug release under external stimulation related to hyperthermia effect. The as-selected microspheres and their chitosan-containing counterparts were biologically assessed on macrophage cultures, being evaluated as biocompatible and bioactive materials that are able to promote cellular adhesion and proliferation. The composite biopolymeric spheres resulted in inhibited microbial growth and biofilm formation, as assessed against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans microbial strains. Significantly improved antimicrobial effects were reported in the case of chitosan-containing biomaterials, regardless of the microorganisms' type. The nanostructured composite biopolymeric spheres evidenced proper characteristics as prolonged and controlled drug release platforms for multipurpose biomedical applications.

Polymeric nanoparticles as carrier for targeted and controlled delivery of anticancer agents

In recent decades, many novel methods by using nanoparticles (NPs) have been investigated for diagnosis, drug delivery and treatment of cancer. Accordingly, the potential of NPs as carriers is very significant for the delivery of anticancer drugs, because cancer treatment with NPs has led to the improvement of some of the drug delivery limitations such as low blood circulation time and bioavailability, lack of water solubility, drug adverse effect. In addition, the NPs protect drugs against enzymatic degradation and can lead to the targeted and/or controlled release of the drug. The present review focuses on the potential of NPs that can help the targeted and/or controlled delivery of anticancer agents for cancer therapy.

Nanocomposites as biomolecules delivery agents in nanomedicine

Nanoparticles (NPs) are atomic clusters of crystalline or amorphous structure that possess unique physical and chemical properties associated with a size range of between 1 and 100 nm. Their nano-sized dimensions, which are in the same range as those of vital biomolecules, such as antibodies, membrane receptors, nucleic acids, and proteins, allow them to interact with different structures within living organisms. Because of these features, numerous nanoparticles are used in medicine as delivery agents for biomolecules. However, off-target drug delivery can cause serious side effects to normal tissues and organs. Considering this issue, it is essential to develop bioengineering strategies to significantly reduce systemic toxicity and improve therapeutic effect. In contrast to passive delivery, nanosystems enable to obtain enhanced therapeutic efficacy, decrease the possibility of drug resistance, and reduce side effects of "conventional" therapy in cancers. The present review provides an overview of the most recent (mostly last 3 years) achievements related to different biomolecules used to enable targeting capabilities of highly diverse nanoparticles. These include monoclonal antibodies, receptor-specific peptides or proteins, deoxyribonucleic acids, ribonucleic acids, [DNA/RNA] aptamers, and small molecules such as folates, and even vitamins or carbohydrates.

Synthesis of multifunctional Fe3O4@PLGA-PEG nano-niosomes as a targeting carrier for treatment of cervical cancer

A new folic acid (FA)-conjugated poly (lactic-co-glycolicacid) (PLGA)-polyethylene glycol (PEG) nano-noisome was prepared. The noisome was employed as a drug delivery system to load curcumin (Cur) as a model drug and fluorescent probe for cervical cancer therapy and cell imaging. The Fe₃O₄@PLGA-PEG@FA noisomes were prepared through facile emulsion solvent evaporation and conjugation chemistry method, possessing the properties of high rapid magnetic separation and targeting character. X-ray photoelectron spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM) were adopted to characterize the chemical structure and properties of these niosomes. MTT assay revealed that the blank noisomes exhibited excellent biocompatibility. The in vitro drug loading and release behavior studier showed the as prepared nano-noisome presented ultrahigh performance as drug carrier. The confocal laser scanning microscopy (CLSM) and flow cytometry (FCM) experiments demonstrated that Cur-loaded Fe₃O₄@PLGA-PEG@FA niosomes achieved significantly high targeting efficiency for cervical cancer. Additionally, the FA-targeted niosomes exhibited higher antitumor efficiency than free Cur. Cell morphology, the mitochondrial membrane potential and cell cycle changes indicated that Cur-loaded niosomes induced HeLa229 cells to apoptosis by destroying mitochondrion of cervical tumor cells, simultaneously changing nuclear morphology and blocking tumor cell proliferation. These results demonstrate that Fe₃O₄@PLGA-PEG@FA noisomes have promising applications as targeted drug delivery system for sustained drug release in cancer treatment.