Accumulating nanoparticles by EPR: A route of no return

A Concise Review on Effect of PEGylation on the Properties of Lipid-Based Nanoparticles

Nanoparticle-based drug delivery systems have emerged as promising platforms for enhancing therapeutic efficacy while minimizing off-target effects. Among various strategies employed to optimize these systems, polyethylene glycol (PEG) modification, known as PEGylation-the covalent attachment of PEG to nanoparticles, has gained considerable attention for its ability to impart stealth properties to nanoparticles while also extending circulation time and improving biocompatibility. PEGylation extends to different drug delivery systems, in specific, nanoparticles for targeting cancer cells, where the concentration of drug in the cancer cells is improved by virtue of PEGylation. The primary challenge linked to PEGylation lies in its confirmation. Numerous research findings provide comprehensive insights into selecting PEG for various PEGylation methods. In this review, we have endeavored to consolidate the outcomes concerning the choice of PEG and diverse PEGylation techniques.

Chitosan-based hybrid nanospheres for vessel normalization towards enhancing tumor chemotherapy

Vessel normalization has proved imperative in tumor growth inhibition. In this work, biopolymer-based hybrid nanospheres capable of normalizing blood vessels were designed to improve the therapeutic effect of chemotherapeutic drugs. Zn0.4Fe2.6O4 nanoparticles (ZFO NPs) were synthesized, and were encapsulated in cross-inked chitosan (CS) along with a nitric oxide (NO) precursor, DETA NONOate, forming hybrid ZFO/NO@CS nanospheres highly stable in physiological environment. The structure, morphology and size of the nanospheres were characterized. The ZFO/NO@CS nanospheres could release NO under acidic conditions typical of intratumoral and intracellular environment. The results of related factors expression, wound healing and tube formation assays demonstrated that both the encapsulated ZFO NPs and the released NO were able to inhibit angiogenesis in tumors. The ZFO/NO@CS nanospheres enhanced the antitumor efficacy of the chemotherapeutic drug DOX by normalizing tumor vessels, as evidenced by in vivo experiments for CT26 tumor-bearing mice. By analyzing the contents of Fe in the tumor and different organs, the nanospheres were found to accumulate primarily at the tumor site. The blood analysis showed little side effect of the nanospheres. The ZFO/NO@CS nanospheres have great potential in improving tumor therapeutic effect when used in combination with chemotherapeutic drugs.

Multibarrier-penetrating drug delivery systems for deep tumor therapy based on synergistic penetration strategy

Nanotherapies, valued for their high efficacy and low toxicity, frequently serve as antitumor treatments, but do not readily penetrate deep into tumor tissues and cells. Here we developed an improved tumor-penetrating peptide (TPP)-based drug delivery system. Briefly, the established TPP iNGR was modified to generate a linear NGR peptide capable of transporting nanotherapeutic drugs into tumors through a CendR pathway-dependent, neuropilin-1 receptor-mediated process. Although TPPs have been reported to reach intended tumor targets, they often fail to penetrate cell membranes to deliver tumoricidal drugs to intracellular targets. We addressed this issue by harnessing cell penetrating peptide technology to develop a liposome-based multibarrier-penetrating delivery system (mbPDS) with improved synergistic drug penetration into deep tumor tissues and cells. The system incorporated doxorubicin-loaded liposomes coated with nona-arginine (R9) CPP and cyclic iNGR (CRNGRGPDC) molecules, yielding Lip-mbPDS. Lip-mbPDS tumor-targeting, tumor cell/tissue-penetrating and antitumor capabilities were assessed using CD13-positive human fibrosarcoma-derived cell (HT1080)-based in vitro and in vivo tumor models. Lip-mbPDS evaluation included three-dimensional layer-by-layer confocal laser scanning microscopy, cell internalization/toxicity assays, three-dimensional tumor spheroid-based penetration assays and antitumor efficacy assays conducted in an animal model. Lip-mbPDS provided enhanced synergistic drug penetration of multiple biointerfaces for potentially deep tumor therapeutic outcomes.

Engineered extracellular vesicles: A new approach for targeted therapy of tumors and overcoming drug resistance

Targeted delivery of anti-tumor drugs and overcoming drug resistance in malignant tumor cells remain significant clinical challenges. However, there are only few effective methods to address these issues. Extracellular vesicles (EVs), actively secreted by cells, play a crucial role in intercellular information transmission and cargo transportation. Recent studies have demonstrated that engineered EVs can serve as drug delivery carriers and showed promising application prospects. Nevertheless, there is an urgent need for further improvements in the isolation and purification of EVs, surface modification techniques, drug assembly processes, and precise recognition of tumor cells for targeted drug delivery purposes. In this review, we summarize the applications of engineered EVs in cancer treatment and overcoming drug resistance, and current challenges associated with engineered EVs are also discussed. This review aims to provide new insights and potential directions for utilizing engineered EVs as targeted delivery systems for anti-tumor drugs and overcoming drug resistance in the near future.

Exosome-based delivery strategies for tumor therapy: an update on modification, loading, and clinical application

Malignancy is a major public health problem and among the leading lethal diseases worldwide. Although the current tumor treatment methods have therapeutic effect to a certain extent, they still have some shortcomings such as poor water solubility, short half-life, local and systemic toxicity. Therefore, how to deliver therapeutic agent so as to realize safe and effective anti-tumor therapy become a problem urgently to be solved in this field. As a medium of information exchange and material transport between cells, exosomes are considered to be a promising drug delivery carrier due to their nano-size, good biocompatibility, natural targeting, and easy modification. In this review, we summarize recent advances in the isolation, identification, drug loading, and modification of exosomes as drug carriers for tumor therapy alongside their application in tumor therapy. Basic knowledge of exosomes, such as their biogenesis, sources, and characterization methods, is also introduced herein. In addition, challenges related to the use of exosomes as drug delivery vehicles are discussed, along with future trends. This review provides a scientific basis for the application of exosome delivery systems in oncological therapy.

Effects of Skeleton Structure of Mesoporous Silica Nanoadjuvants on Cancer Immunotherapy

Mesoporous silica nanoparticles (MSNs) have been widely praised as nanoadjuvants in vaccine/tumor immunotherapy thanks to their excellent biocompatibility, easy-to-modify surface, adjustable particle size, and remarkable immuno-enhancing activity. However, the application of MSNs is still greatly limited by some severe challenges including the unclear and complicated relationships of structure and immune effect. Herein, three commonly used MSNs with different skeletons including MSN with tetrasulfide bonds (TMSN), MSN containing ethoxy framework (EMSN), and pure -Si-O-Si- framework of MSN (MSN) are comprehensively compared to study the impact of chemical construction on immune effect. The results fully demonstrate that the three MSNs have great promise in improving cellular immunity for tumor immunotherapy. Moreover, the TMSN performs better than the other two MSNs in antigen loading, cellular uptake, reactive oxygen species (ROS) generation, lymph node targeting, immune activation, and therapeutic efficiency. The findings provide a new paradigm for revealing the structure-function relationship of mesoporous silica nanoadjuvants, paving the way for their future clinical application.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

Surface Functionalization of Gold Nanoparticles for Targeting the Tumor Microenvironment to Improve Antitumor Efficiency

Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.

Recent Progress of Preparation Strategies in Organic Nanoparticles for Cancer Phototherapeutics

Phototherapy has the advantages of being a highly targeted, less toxic, less invasive, and repeatable treatment, compared with conventional treatment methods such as surgery, chemotherapy, and radiotherapy. The preparation strategies are significant in order to determine the physical and chemical properties of nanoparticles. However, choosing appropriate preparation strategies to meet applications is still challenging. This review summarizes the recent progress of preparation strategies in organic nanoparticles, mainly focusing on the principles, methods, and advantages of nanopreparation strategies. In addition, typical examples of cancer phototherapeutics are introduced in detail to inform the choice of appropriate preparation strategies. The relative future trend and outlook are preliminarily proposed.

Recent Studies and Progress in the Intratumoral Administration of Nano-Sized Drug Delivery Systems

Over the last 30 years, diverse types of nano-sized drug delivery systems (nanoDDSs) have been intensively explored for cancer therapy, exploiting their passive tumor targetability with an enhanced permeability and retention effect. However, their systemic administration has aroused some unavoidable complications, including insufficient tumor-targeting efficiency, side effects due to their undesirable biodistribution, and carrier-associated toxicity. In this review, the recent studies and advancements in intratumoral nanoDDS administration are generally summarized. After identifying the factors to be considered to enhance the therapeutic efficacy of intratumoral nanoDDS administration, the experimental results on the application of intratumoral nanoDDS administration to various types of cancer therapies are discussed. Subsequently, the reports on clinical studies of intratumoral nanoDDS administration are addressed in short. Intratumoral nanoDDS administration is proven with its versatility to enhance the tumor-specific accumulation and retention of therapeutic agents for various therapeutic modalities. Specifically, it can improve the efficacy of therapeutic agents with poor bioavailability by increasing their intratumoral concentration, while minimizing the side effect of highly toxic agents by restricting their delivery to normal tissues. Intratumoral administration of nanoDDS is considered to expand its application area due to its potent ability to improve therapeutic effects and relieve the systemic toxicities of nanoDDSs.

pH-Sensitive Hybrid System Based on Eu3+/Gd3+ Co-Doped Hydroxyapatite and Mesoporous Silica Designed for Theranostic Applications

Nanomaterials such as pH-responsive polymers are promising for targeted drug delivery systems, due to the difference in pH between tumor and healthy regions. However, there is a significant concern about the application of these materials in this field due to their low mechanical resistance, which can be attenuated by combining these polymers with mechanically resistant inorganic materials such as mesoporous silica nanoparticles (MSN) and hydroxyapatite (HA). Mesoporous silica has interesting properties such as high surface area and hydroxyapatite has been widely studied to aid in bone regeneration, providing special properties adding multifunctionality to the system. Furthermore, fields of medicine involving luminescent elements such as rare earth elements are an interesting option in cancer treatment. The present work aims to obtain a pH-sensitive hybrid system based on silica and hydroxyapatite with photoluminescent and magnetic properties. The nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption methods, CHN elemental analysis, Zeta Potential, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), vibrational sample magnetometry (VSM), and photoluminescence analysis. Incorporation and release studies of the antitumor drug doxorubicin were performed to evaluate the potential use of these systems in targeted drug delivery. The results showed the luminescent and magnetic properties of the materials and showed suitable characteristics for application in the release of pH-sensitive drugs.

Superparamagnetic iron oxide nanoparticles target BxPC-3 cells and silence MUC4 for theranostics of pancreatic cancer

PURPOSE

Superparamagnetic iron oxide nanoparticles (SPION) are excellent magnetic resonance imaging (MRI) contrast agents. Mucin 4 (MUC4) acts as pancreatic cancer (PC) tumor antigen and influences PC progression. Small interfering RNAs (siRNAs) are used as a gene-silencing tool to treat a variety of diseases.

METHODS

We designed a therapeutic probe based on polyetherimide-superparamagnetic iron oxide nanoparticles (PEI-SPION) combined with siRNA nanoprobes (PEI-SPION-siRNA) to assess the contrast in MRI. The biocompatibility of the nanocomposite, and silencing of MUC4 were characterized and evaluated.

RESULTS

The prepared molecular probe had a particle size of 61.7 ± 18.5 nmand a surface of 46.7 ± 0.8mVand showed good biocompatibility in vitro and T2 relaxation efficiency. It can also load and protect siRNA. PEI-SPION-siRNA showed a good silencing effect on MUC4.

CONCLUSION

PEI-SPION-siRNA may be beneficial as a novel theranostic tool for PC.

Co-delivery of doxorubicin and hydroxychloroquine via chitosan/alginate nanoparticles for blocking autophagy and enhancing chemotherapy in breast cancer therapy

Breast cancer (BC) is the most common malignancy in women worldwide, and the standard treatment is chemotherapy or radiotherapy after surgery. In order to reduce the side effects of chemotherapy, various nanoparticles (NPs) have been discovered and synthesized, which has become a promising treatment for BC. In this study, a co-delivery nanodelivery drug system (Co-NDDS) was designed and synthesized with 2,3-dimercaptosuccinic acid (DMSA) coated Fe₃O₄ NPs as core encapsulated into chitosan/alginate nanoparticles (CANPs) shell, doxorubicin (DOX) and hydroxychloroquine (HCQ) as loading drugs. Smaller NPs carrying DOX (FeAC-DOX NPs) were loaded into larger NPs containing HCQ (FeAC-DOX@PC-HCQ NPs) by ionic gelation and emulsifying solvent volatilization methods. The physicochemical properties of this Co-NDDS were characterised, followed by in vitro studies of the anticancer effects and mechanisms using two different BC cell lines, MCF-7 cells and MDA-MB-231 cells. The results indicated that the Co-NDDS showcases exemplary physicochemical qualities and encapsulation capacity, facilitating accurate intracellular release through pH-sensitive attributes. Importantly, NPs can significantly increase the in vitro cytotoxicity of co-administered drugs and effectively inhibit the autophagy level of tumour cells. The Co-NDDS constructed in this study provides a promising strategy for the treatment of BC.

Selection of an aggregation-caused quenching-based fluorescent tracer for imaging studies in nano drug delivery systems

In order to develop and optimize nano drug delivery systems (NDDSs), it is crucial to understand their in vivo fate. We previously found that P2 (Aza-BODIPY) and P4 (BODIPY) as aggregation-caused quenching (ACQ) probes could be used to unravel the biofate of various nanoparticles owing to their water-sensitive emission. However, previous studies also found that quenched ACQ probe aggregates showed repartition into hydrophobic physiologically relevant constituents, resulting in fluorescence re-illumination. In this paper, we screened various types of fluorophores for ACQ and their re-illumination performance and focused on Aza-BODIPY dyes. BODIPY and Aza-BODIPY dyes were identified to be advantageous over other fluorophores. Some BODIPY and Aza-BODIPY dyes were selected as potential probes with improved performance against re-illumination. The best performing probes were Aza-C7 and Aza-C8. Aza-C7-loaded PMs were found to have decreased fluorescence re-illumination properties over P2 and DiR.

Nanotherapy based on magneto-mechanochemical modulation of tumor redox state

Magnetic nanoparticles (MNs) are typically used as contrast agents for magnetic resonance imaging or as drug carriers with a remotely controlled delivery to the tumor. However, they can also potentiate the action of anticancer drugs under the influence of applied constant magnetic (CMFs) and electromagnetic fields (EMFs). This review demonstrates the role of magneto-mechanochemical effects produced by MNs alone and loaded with anticancer agents (MNCs) in response to CMFs and EMFs for modulation of tumor redox state. The combined treatment is suggested to act by two mechanisms: spin-dependent electron transport propagates free radical chain reactions, while magnetomechanical interactions cause conformational changes in drug molecules loaded onto MNs and generate reactive oxygen species (ROS). By adjusting the parameters of CMFs and EMFs during the magneto-mechanochemical synthesis and subsequent treatment, it is possible to modulate ROS production and switch redox signaling involved in ERK1/2 and NF-κB pathways from initiation of tumor growth to inhibition. Observations of tumor volume in different animal models and treatment combinations reported a 6%-70% reduction as compared with conventional drugs. Despite these results, there is a general lack of research in magnetic nanotheranostics that link redox changes across multiple levels of organization in the tumor-bearing host. Further multidisciplinary studies with more focus on the relationship between the electron transport processes in biomolecules and their effects on the tumor-host interaction should accelerate the clinical translation of magnetic nanotheranostics. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

A comprehensive review of advanced drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic autoimmune disease, is characterized by articular pain and swelling, synovial hyperplasia, and cartilage and bone destruction. Conventional treatment strategies for RA involve the use of anti-rheumatic drugs, which warrant high-dose, frequent, and long-term administration, resulting in serious adverse effects and poor patient compliance. To overcome these problems and improve clinical efficacy, drug delivery systems (DDS) have been designed for RA treatment. These systems have shown success in animal models of RA. In this review, representative DDS that target RA through passive or active effects on inflammatory cells are discussed and highlighted using examples. In particular, DDS allowing controlled and targeted drug release based on a variety of stimuli, intra-articular DDS, and transdermal DDS for RA treatment are described. Thus, this review provides an improved understanding of these DDS and paves the way for the development of novel DDS for efficient RA treatment.

Exploring the Long-Term Tissue Accumulation and Excretion of 3 nm Cerium Oxide Nanoparticles after Single Dose Administration

Nanoparticle (NP) pharmacokinetics significantly differ from traditional small molecule principles. From this emerges the need to create new tools and concepts to harness their full potential and avoid unnecessary risks. Nanoparticle pharmacokinetics strongly depend on size, shape, surface functionalisation, and aggregation state, influencing their biodistribution, accumulation, transformations, and excretion profile, and hence their efficacy and safety. Today, while NP biodistribution and nanoceria biodistribution have been studied often at short times, their long-term accumulation and excretion have rarely been studied. In this work, 3 nm nanoceria at 5.7 mg/kg of body weight was intravenously administrated in a single dose to healthy mice. Biodistribution was measured in the liver, spleen, kidney, lung, brain, lymph nodes, ovary, bone marrow, urine, and faeces at different time points (1, 9, 30, and 100 days). Biodistribution and urinary and faecal excretion were also studied in rats placed in metabolic cages at shorter times. The similarity of results of different NPs in different models is shown as the heterogeneous nanoceria distribution in organs. After the expectable accumulation in the liver and spleen, the concentration of cerium decays exponentially, accounting for about a 50% excretion of cerium from the body in 100 days. Cerium ions, coming from NP dissolution, are most likely excreted via the urinary tract, and ceria nanoparticles accumulated in the liver are most likely excreted via the hepatobiliary route. In addition, nanoceria looks safe and does not damage the target organs. No weight loss or apathy was observed during the course of the experiments.

An EGCG-mediated self-assembled micellar complex acts as a bioactive drug carrier

Epigallocatechin gallate (EGCG) has attracted the increasing attention of many researchers, especially in the field of tumor therapy. However, EGCG has poor fat solubility, low stability, low bioavailability, and a high effective dose in vivo. Traditional drug delivery methods are difficult to deliver the water-soluble EGCG efficiently and in high doses to tumor sites. To address these issues, a new type of strategy has been tried in this study to transform EGCG from a "Bioactive natural ingredient" into a "Bioactive drug carrier". Briefly, the EGCG was modified with a fat-soluble 9-fluorene methoxy carbonyl (Fmoc) motif, and the obtained EGCG-Fmoc showed a considerable improvement in lipid solubility and stability. Interestingly, EGCG-Fmoc obtained the characteristic of self-assembly in water, making it easier to take up by tumor cells. Furthermore, the self-assembled nanocomplex exhibited paclitaxel encapsulation performance and could achieve the dual delivery of EGCG and paclitaxel.

Harnessing Engineered Immune Cells and Bacteria as Drug Carriers for Cancer Immunotherapy

Immunotherapy continues to be in the spotlight of oncology therapy research in the past few years and has been proven to be a promising option to modulate one's innate and adaptive immune systems for cancer treatment. However, the poor delivery efficiency of immune agents, potential off-target toxicity, and nonimmunogenic tumors significantly limit its effectiveness and extensive application. Recently, emerging biomaterial-based drug carriers, including but not limited to immune cells and bacteria, are expected to be potential candidates to break the dilemma of immunotherapy, with their excellent natures of intrinsic tumor tropism and immunomodulatory activity. More than that, the tiny vesicles and physiological components derived from them have similar functions with their source cells due to the inheritance of various surface signal molecules and proteins. Herein, we presented representative examples about the latest advances of biomaterial-based delivery systems employed in cancer immunotherapy, including immune cells, bacteria, and their derivatives. Simultaneously, opportunities and challenges of immune cells and bacteria-based carriers are discussed to provide reference for their future application in cancer immunotherapy.

Preclinical PET and MR Evaluation of 89Zr- and 68Ga-Labeled Nanodiamonds in Mice over Different Time Scales

Nanodiamonds (NDs) have high potential as a drug carrier and in combination with nitrogen vacancies (NV centers) for highly sensitive MR-imaging after hyperpolarization. However, little remains known about their physiological properties in vivo. PET imaging allows further evaluation due to its quantitative properties and high sensitivity. Thus, we aimed to create a preclinical platform for PET and MR evaluation of surface-modified NDs by radiolabeling with both short- and long-lived radiotracers. Serum albumin coated NDs, functionalized with PEG groups and the chelator deferoxamine, were labeled either with zirconium-89 or gallium-68. Their biodistribution was assessed in two different mouse strains. PET scans were performed at various time points up to 7 d after i.v. injection. Anatomical correlation was provided by additional MRI in a subset of animals. PET results were validated by ex vivo quantification of the excised organs using a gamma counter. Radiolabeled NDs accumulated rapidly in the liver and spleen with a slight increase over time, while rapid washout from the blood pool was observed. Significant differences between the investigated radionuclides were only observed for the spleen (1 h). In summary, we successfully created a preclinical PET and MR imaging platform for the evaluation of the biodistribution of NDs over different time scales.

Co-delivery of gemcitabine and salinomycin in PEGylated liposomes for enhanced anticancer efficacy against colorectal cancer

Colorectal cancer remains one of the major causes of morbidity and mortality in both developed and emerging countries. Cancer stem cells (CSCs) are a subpopulation of cells within the tumor mass harboring stem cell characteristics, considered responsible for tumor initiation, growth, relapse, and treatment failure. Lately, it has become clear that both CSCs and non-CSCs have to be eliminated for the successful eradication of cancer. Drug delivery systems have been extensively employed to enhance drug efficacy. In this study, salinomycin (SAL), a selective anti-CSC drug, and gemcitabine (GEM), a conventional anticancer drug, were co-loaded in liposomes and tested for optimal therapeutic efficacy. We employed the Design of Experiments approach to develop and optimize a liposomal delivery system for GEM and SAL. The antiproliferative effect of the liposomes was evaluated in SW-620 human colorectal cancer cells. The GEM and SAL-loaded liposomes exhibited adequate size, polydispersity, zeta potential, and drug content. The in vitro release study showed a sustained release of GEM and SAL from the liposomes over 72 h. Moreover, no sign of liposome aggregation was seen over 1 month and in a biological medium (FBS). The in vitro cytotoxic effects of the co-loaded liposomes were superior to that of single GEM either in free or liposomal form. The combination therapy using GEM and SAL co-loaded in liposomes could be a promising strategy for tackling colorectal cancer.

Cell-Derived Vesicles for Nanoparticles' Coating: Biomimetic Approaches for Enhanced Blood Circulation and Cancer Therapy

Cancer nanomedicines are designed to encapsulate different therapeutic agents, prevent their premature release, and deliver them specifically to cancer cells, due to their ability to preferentially accumulate in tumor tissue. However, after intravenous administration, nanoparticles immediately interact with biological components that facilitate their recognition by the immune system, being rapidly removed from circulation. Reports show that less than 1% of the administered nanoparticles effectively reach the tumor site. This suboptimal pharmacokinetic profile is pointed out as one of the main factors for the nanoparticles' suboptimal therapeutic effectiveness and poor translation to the clinic. Therefore, an extended blood circulation time may be crucial to increase the nanoparticles' chances of being accumulated in the tumor and promote a site-specific delivery of therapeutic agents. For that purpose, the understanding of the forces that govern the nanoparticles' interaction with biological components and the impact of the physicochemical properties on the in vivo fate will allow the development of novel and more effective nanomedicines. Therefore, in this review, the nano-bio interactions are summarized. Moreover, the application of cell-derived vesicles for extending the blood circulation time and tumor accumulation is reviewed, focusing on the advantages and shortcomings of each cell source.

Tumor vascular heterogeneity and the impact of subtumoral nanoemulsion biodistribution

Aim: Investigate the heterogeneous tumor tissue organization and examine how this condition can interfere with the passive delivery of a lipid nanoemulsion in two breast cancer preclinical models (4T1 and Ehrlich). Materials & methods: The authors used in vivo image techniques to follow the nanoemulsion biodistribution and microtomography, as well as traditional histopathology and electron microscopy to evaluate the tumor structural characteristics. Results & conclusion: Lipid nanoemulsion was delivered to the tumor, vascular organization depends upon the subtumoral localization and this heterogeneous organization promotes a nanoemulsion biodistribution to the highly vascular peripherical region. Also, the results are presented with a comprehensive mathematical model, describing the differential biodistribution in two different breast cancer models, the 4T1 and Ehrlich models.

Inflammation-Regulated Nanodrug Sensitizes Hepatocellular Carcinoma to Checkpoint Blockade Therapy by Reprogramming the Tumor Microenvironment

Immune checkpoint blockade (ICB) utilizing programmed death ligand-1 (PD-L1) antibody is a promising treatment strategy in solid tumors. However, in fact, more than half of hepatocellular carcinoma (HCC) patients are unresponsive to PD-L1-based ICB treatment due to multiple immune evasion mechanisms such as the hyperactivation of inflammation pathway, excessive tumor-associated macrophages (TAMs) infiltration, and insufficient infiltration of T cells. Herein, an inflammation-regulated nanodrug was designed to codeliver NF-κB inhibitor curcumin and PD-L1 antibody to reprogram the tumor microenvironment (TME) and activate antitumor immunity. The nanodrug accumulated in TME by an enhanced permeability and retention effect, where it left antibody to block PD-L1 on the membrane of tumor cells and TAMs due to pH-responsiveness. Simultaneously, a new curcumin-encapsulated nanodrug was generated, which was easily absorbed by either tumor cells or TAMs to inhibit the nuclear factor kappa-B (NF-κB) signal and related immunosuppressive genes. The inflammation-regulated nanodrug possessed good biocompatibility. Simultaneously, it reprogrammed TME effectively and exhibited an effective anticancer effect in immunocompetent mice. Overall, this study provided a potent strategy to improve the efficiency of ICB-based treatment for HCC.

Disulfiram enhances chemotherapeutic effects of doxorubicin liposomes against human hepatocellular carcinoma via activating ROS-induced cell stress response pathways

PURPOSE

Increasing evidences have revealed the anti-cancer effect of disulfiram. Current disulfiram-based cancer therapies still have limitations, such as poor tumor-targeting ability and insufficient studies on anti-tumor mechanisms.

METHODS

In the present study, tumor-targeting liposomes were prepared as drug carriers to increase retention of disulfiram in tumor cells. Then, anti-tumor efficacy of liposomes and the underlying mechanisms were investigated in in vitro, in vivo, and transcriptomic level.

RESULTS

The results showed that disulfiram enhanced sensitivity of human hepatocellular carcinoma cells to doxorubicin by 15-27-fold, and increased reactive oxygen species (ROS) production as well as caspase-dependent apoptosis. Inhibition of tumor migration and invasion by doxorubicin were further enhanced by disulfiram. In vivo study showed that disulfiram additive doxorubicin liposomes had better performance in suppressing tumor growth than single doxorubicin liposomes. Gene expression profiling found that cellular components destruction, cell stress, check point regulation, and immunoregulation were the main anti-tumor mechanisms of disulfiram. More importantly, disulfiram possessed a great potential to be a protein ubiquitination and murine double minute 4 (MDM4) targeting compound.

CONCLUSIONS

Due to its low price and good safety, it is worth to repurposing disulfiram as a chemotherapeutic drug. Furthermore, MDM4 may act as a biomarker for observation the clinical effect of disulfiram-based treatment.

Exosomes and mimics as novel delivery platform for cancer therapy

Exosomes are nano-sized biological extracellular vesicles transmitting information between cells and constituting a new intercellular communication mode. Exosomes have many advantages as an ideal drug delivery nanocarrier, including good biocompatibility, permeability, low toxicity, and low immunogenicity. Recently, exosomes have been used to deliver chemotherapeutic agents, natural drugs, nucleic acid drugs, and other antitumor drugs to treat many types of tumors. Due to the limited production of exosomes, synthetic exosome-mimics have been developed as an ideal platform for drug delivery. This review summarizes recent advances in the application of exosomes and exosome-mimics delivering therapeutic drugs in treating cancers.

The Yin and Yang of the protein corona on the delivery journey of nanoparticles

Nanoparticles-based drug delivery systems have attracted significant attention in biomedical fields because they can deliver loaded cargoes to the target site in a controlled manner. However, tremendous challenges must still be overcome to reach the expected targeting and therapeutic efficacy in vivo. These challenges mainly arise because the interaction between nanoparticles and biological systems is complex and dynamic and is influenced by the physicochemical properties of the nanoparticles and the heterogeneity of biological systems. Importantly, once the nanoparticles are injected into the blood, a protein corona will inevitably form on the surface. The protein corona creates a new biological identity which plays a vital role in mediating the bio-nano interaction and determining the ultimate results. Thus, it is essential to understand how the protein corona affects the delivery journey of nanoparticles in vivo and what we can do to exploit the protein corona for better delivery efficiency. In this review, we first summarize the fundamental impact of the protein corona on the delivery journey of nanoparticles. Next, we emphasize the strategies that have been developed for tailoring and exploiting the protein corona to improve the transportation behavior of nanoparticles in vivo. Finally, we highlight what we need to do as a next step towards better understanding and exploitation of the protein corona. We hope these insights into the "Yin and Yang" effect of the protein corona will have profound implications for understanding the role of the protein corona in a wide range of nanoparticles.

Nanoparticles-Based Strategies to Improve the Delivery of Therapeutic Small Interfering RNA in Precision Oncology

Small interfering RNA (siRNA) can selectively suppress the expression of disease-causing genes, holding great promise in the treatment of human diseases, including malignant cancers. In recent years, with the development of chemical modification and delivery technology, several siRNA-based therapeutic drugs have been approved for the treatment of non-cancerous liver diseases. Nevertheless, the clinical development of siRNA-based cancer therapeutics remains a major translational challenge. The main obstacles of siRNA therapeutics in oncology include both extracellular and intracellular barriers, such as instability under physiological conditions, insufficient tumor targeting and permeability (particularly for extrahepatic tumors), off-target effects, poor cellular uptake, and inefficient endosomal escape. The development of clinically suitable and effective siRNA delivery systems is expected to overcome these challenges. Herein, we mainly discuss recent strategies to improve the delivery and efficacy of therapeutic siRNA in cancer, including the application of non-viral nanoparticle-based carriers, the selection of target genes for therapeutic silencing, and the combination with other therapeutic modalities. In addition, we also provide an outlook on the ongoing challenges and possible future developments of siRNA-based cancer therapeutics during clinical translation.

PEGylated solid lipid nanoparticles functionalized by aptamer for targeted delivery of docetaxel in mice bearing C26 tumor

OBJECTIVE

Colorectal cancer is one of the most deadly cancers in the world. Docetaxel (DTX) is a potentially important chemotherapeutic agent for the treatment of cancer. Many studies have attempted to improve its bioavailability and efficiency using different nanoparticulate drug delivery systems.

SIGNIFICANCE

In the current study, PEGylated solid lipid nanoparticles (SLNs) containing DTX were prepared and modified with AS1411 anti-nucleolin aptamers to target nucleoin receptors on colorectal cancer cells.

METHODS

Nanoparticles were characterized and the morphology was evaluated. In vitro studies were investigated on murine colon carcinoma (C26) and Chinese hamster ovary (CHO) cell lines. Then in vivo antitumor efficacy and survival analysis were evaluated in mice bearing the C26 tumor model.

RESULTS

Results showed 135-140 nm particle size and about 78% DTX entrapment efficiency for actively targeted samples. PEGylated and aptamer-targeted SLNs containing DTX had the lowest IC₅₀ (0.28 and 0.11 nM for 3 and 6 h incubation respectively) and higher cellular uptake values in the C26 cell line. Also in vivo results demonstrated that PEGylated and aptamer-targeted SLNs containing Docetaxel (Apt-PEG-SLN-DTX) improved antitumor activity and inhibited tumor growth in C26 tumor-bearing mice.

CONCLUSION

These results suggested that PEGylated and aptamer-targeted SLNs containing DTX exhibited efficient characteristics in tumor inhibitory against murine C26 carcinoma model.

Enhanced Permeability and Retention Effect: A key facilitator for solid tumor targeting by nanoparticles

Exploring the enhanced permeability and retention (EPR) effect through therapeutic nanoparticles has been a subject of considerable interest in tumor biology. This passive targeting based phenomenon exploits the leaky blood vasculature and the defective lymphatic drainage system of the heterogeneous tumor microenvironment resulting in enhanced preferential accumulation of the nanoparticles within the tumor tissues. This article reviews the fundamental studies to assess how the EPR effect plays an essential role in passive targeting. Further, it summarizes various therapeutic modalities of nanoformulation including chemo-photodynamic therapy, intravascular drug release, and photothermal immunotherapy to combat cancer using enhanced EPR effect in neoplasia region.

The Pyrazolo[3,4-d]Pyrimidine Derivative Si306 Encapsulated into Anti-GD2-Immunoliposomes as Therapeutic Treatment of Neuroblastoma

Si306, a pyrazolo[3,4-d]pyrimidine derivative recently identified as promising anticancer agent, has shown favorable in vitro and in vivo activity profile against neuroblastoma (NB) models by acting as a competitive inhibitor of c-Src tyrosine kinase. Nevertheless, Si306 antitumor activity is associated with sub-optimal aqueous solubility, which might hinder its further development. Drug delivery systems were here developed with the aim to overcome this limitation, obtaining suitable formulations for more efficacious in vivo use. Si306 was encapsulated in pegylated stealth liposomes, undecorated or decorated with a monoclonal antibody able to specifically recognize and bind to the disialoganglioside GD2 expressed by NB cells (LP[Si306] and GD2-LP[Si306], respectively). Both liposomes possessed excellent morphological and physio-chemical properties, maintained over a period of two weeks. Compared to LP[Si306], GD2-LP[Si306] showed in vitro specific cellular targeting and increased cytotoxic activity against NB cell lines. After intravenous injection in healthy mice, pharmacokinetic profiles showed increased plasma exposure of Si306 when delivered by both liposomal formulations, compared to that obtained when Si306 was administered as free form. In vivo tumor homing and cytotoxic effectiveness of both liposomal formulations were finally tested in an orthotopic animal model of NB. Si306 tumor uptake resulted significantly higher when encapsulated in GD2-LP, compared to Si306, either free or encapsulated into untargeted LP. This, in turn, led to a significant increase in survival of mice treated with GD2-LP[Si306]. These results demonstrate a promising antitumor efficacy of Si306 encapsulated into GD2-targeted liposomes, supporting further therapeutic developments in pre-clinical trials and in the clinic for NB.

Magnetic Nanoparticles in Medicine: Progress, Problems, and Advances

The review presents an analysis of the current state of research related to the design, development, and practical application of methods for biomedical radioelectronics and nanomedicine, including the use of magnetic nanoparticles. The important role of rational scientific physical approaches and experimental methods in the design of efficient and safe magnetic nanoparticle-based agents for therapy, controlled targeted drug delivery, and diagnostics, including spatial imaging, is emphasized. Examples of successful practical application of magnetic nanoparticles in medicine based on these methods are given, and an analysis of the main problems and prospects of this area of science is conducted.

Smart Lipid-Based Nanosystems for Therapeutic Immune Induction against Cancers: Perspectives and Outlooks

Cancer immunotherapy, a promising and widely applied mode of oncotherapy, makes use of immune stimulants and modulators to overcome the immune dysregulation present in cancer, and leverage the host's immune capacity to eliminate tumors. Although some success has been seen in this field, toxicity and weak immune induction remain challenges. Liposomal nanosystems, previously used as targeting agents, are increasingly functioning as immunotherapeutic vehicles, with potential for delivery of contents, immune induction, and synergistic drug packaging. These systems are tailorable, multifunctional, and smart. Liposomes may deliver various immune reagents including cytokines, specific T-cell receptors, antibody fragments, and immune checkpoint inhibitors, and also present a promising platform upon which personalized medicine approaches can be built, especially with preclinical and clinical potentials of liposomes often being frustrated by inter- and intrapatient variation. In this review, we show the potential of liposomes in cancer immunotherapy, as well as the methods for synthesis and in vivo progression thereof. Both preclinical and clinical studies are included to comprehensively illuminate prospects and challenges for future research and application.

Design and synthesis of targeted star-shaped micelle for guided delivery of camptothecin: In vitro and in vivo evaluation

This study aimed to synthesize a star-shaped micelle using 3-azido-2,2-bis(azidomethyl)propan-1-ol (pentaerythritol triazide) core, as an initiator for the synthesis of three-arm polylactic acid (PLA) block. Then, the ends of the PLA arms were converted to PLA triazide followed by conjugation to the three alkyne-PEG-maleamide through click reaction. The maleamide ends were available for coupling with sulfhydryl-modified DNA aptamer against epithelial cell adhesion molecule in order to offer targeted delivery of encapsulated drug, camptothecin to the site of action. The successful synthesis of the star-shaped polymers was confirmed via¹HNMR. Hydrophobic anti-cancer drug, camptothecin was encapsulated into the micelles core implementing solvent switching method providing loading content (LC%) and encapsulation efficiency (EE%) of 3.7 ± 0.4 and 73.7 ± 8.2, respectively. The size of both non-targeted and aptamer-targeted micelles was determined to be 154 and 192 nm, respectively with polydispersity index below 0.3. In vitro drug release evaluation at 37 °C, pH 7.4 showed a controlled release pattern for camptothecin during 72 h. In vitro cytotoxicity of the prepared non-targeted and targeted micelles was carried out on human colorectal adenocarcinoma (HT29) and mouse colon carcinoma (C26) as EpCAM positive cell lines and Chinese hamster ovary (CHO) as EpCAM negative cell line. The results verified significantly higher cytotoxicity of the targeted micelles on HT29 and C26 cell lines, while no obvious difference was observed between targeted and non-targeted formulation on CHO cell line. The in vivo therapeutic efficiency investigation on BALB/c C26 tumor-bearing mice showed superior capability of the targeted formulation on tumor suppression and survival rate of the treated mice. The developed platform exhibited excellent characteristics to diminish camptothecin drawbacks and its adverse effects while considerably increasing its therapeutic index.

In Vivo Biodistribution, Clearance, and Biocompatibility of Multiple Carbon Dots Containing Nanoparticles for Biomedical Application

Current research on the use of carbon dots for various biological systems mainly focuses on the single carbon dots, while particles that contain multiple carbon dots have scarcely been investigated. Here, we assessed multiple carbon dots-crosslinked polyethyleneimine nanoparticles (CDs@PEI) for their in vivo biodistribution, clearance, biocompatibility, and cellular uptake. The in vivo studies demonstrate three unique features of the CDs@PEI nanoparticles: (1) the nanoparticles possess tumor-targeting ability with steady and prolonged retention time in the tumor region. (2) The nanoparticles show hepatobiliary excretion and are clear from the intestine in feces. (3) The nanoparticles have much better biocompatibility than the polyethyleneimine passivated single carbon dots (PEI-CD). We also found that pegylated CDs@PEI nanoparticles can be effectively taken up by the cells, which the confocal laser scanning microscope can image under different excitation wavelengths (at 405, 488, and 800 nm). These prior studies provide invaluable information and new opportunities for this new type of intrinsic photoluminescence nanoparticles in carbon dot-based biomedical applications.

Development of next generation nanomedicine-based approaches for the treatment of cancer: we've barely scratched the surface

Interest in nanomedicines has grown rapidly over the past two decades, owing to the promising therapeutic applications they may provide, particularly for the treatment of cancer. Personalised medicine and 'smart' actively targeted nanoparticles represent an opportunity to deliver therapies directly to cancer cells and provide sustained drug release, in turn providing overall lower off-target toxicity and increased therapeutic efficacy. However, the successful translation of nanomedicines from encouraging pre-clinical findings to the clinic has, to date, proven arduous. In this review, we will discuss the use of nanomedicines for the treatment of cancer, with a specific focus on the use of polymeric and lipid nanoparticle delivery systems. In particular, we examine approaches exploring the surface functionalisation of nanomedicines to elicit active targeting and therapeutic effects as well as challenges and future directions for nanoparticles in cancer treatment.

Specific delivering of RNAi using Spike's aptamer-functionalized lipid nanoparticles for targeting SARS-CoV-2: A strong anti-Covid drug in a clinical case study

Coronavirus (SARS-CoV-2) as a global pandemic has attracted the attention of many scientific centers to find the right treatment. We expressed and purified the recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein, and specific RBD aptamers were designed using SELEX method. RNAi targeting nucleocapsid phosphoprotein was synthesized and human lung cells were inoculated with aptamer-functionalized lipid nanoparticles (LNPs) containing RNAi. The results demonstrated that RBD aptamer having K_D values of 0.290 nm possessed good affinity. Based on molecular docking and efficacy prediction analysis, siRNA molecule was showed the best action. LNPs were appropriately functionalized by aptamer and contained RNAi molecules. Antiviral assay using q-PCR and ELISA demonstrated that LNP functionalized with 35 µm Apt and containing 30 nm RNAi/ml of cell culture had the best antiviral activity compared to other concentrations. Applied aptamer in the nanocarrier has two important functions. First, it can deliver the drug (RNAi) to the surface of epithelial cells. Second, by binding to the SARS-CoV-2 spike protein, it inhibits the virus entrance into cells. Our data reveal an interaction between the aptamer and the virus, and RNAi targeted the virus RNA. CT scan and the clinical laboratory tests in a clinical case study, a 36-year old man who presented with severe SARS-CoV-2, demonstrated that inhalation of 10 mg Apt-LNPs-RNAi nebulized/day for six days resulted in an improvement in consolidation and ground-glass opacity in lungs on the sixth day of treatment. Our findings suggest the treatment of SARS-CoV-2 infection through inhalation of Aptamer-LNPs-RNAi.

Transfersomes improved delivery of ascorbic palmitate into the viable epidermis for enhanced treatment of melasma

Ascorbic palmitate (AP) is widely used in the topical pharmaceutical or cosmetic formulations for melasma treatment. However, the presence of the skin barriers makes it difficult for the highly lipophilic drug molecules to traverse the stratum corneum (SC) and diffuse into the viable epidermis (EP) to reach the melanocytes, thereby exerting suboptimal antimelasma effects. Herein, AP was encapsulated into the transfersomes (TFs), yielding AP-TFs. AP-TFs utilized the deformability of TFs to squeeze through the skin pores in the SC under the transepidermal hydration gradient forces, leading to 14.1-fold increase in AP accumulation to the EP. AP-TFs could slowly release the encapsulated AP, while whether the released AP or transfersomal AP showed comparable uptake into the melanocytes, thereby exerting similar inhibitory effects on tyrosinase activity and melanogenesis. Ultimately, in the rat melasma model, AP-TFs showed superior antimelasma efficacy to free AP, with effective relief of oxidative stress and inflammation in the skin. Moreover, AP-TFs did not induce skin irritation. Therefore, the study provides a safe and effective approach to elevating the delivery of highly lipophilic drugs to the EP for enhanced treatment of melasma.

Functionalized Nanoparticles Targeting Tumor-Associated Macrophages as Cancer Therapy

The tumor microenvironment (TME) plays a central role in regulating antitumor immune responses. As an important part of the TME, alternatively activated type 2 (M2) macrophages drive the development of primary and secondary tumors by promoting tumor cell proliferation, tumor angiogenesis, extracellular matrix remodeling and overall immunosuppression. Immunotherapy approaches targeting tumor-associated macrophages (TAMs) in order to reduce the immunosuppressive state in the TME have received great attention. Although these methods hold great potential for the treatment of several cancers, they also face some limitations, such as the fast degradation rate of drugs and drug-induced cytotoxicity of organs and tissues. Nanomedicine formulations that prevent TAM signaling and recruitment to the TME or deplete M2 TAMs to reduce tumor growth and metastasis represent encouraging novel strategies in cancer therapy. They allow the specific delivery of antitumor drugs to the tumor area, thereby reducing side effects associated with systemic application. In this review, we give an overview of TAM biology and the current state of nanomedicines that target M2 macrophages in the course of cancer immunotherapy, with a specific focus on nanoparticles (NPs). We summarize how different types of NPs target M2 TAMs, and how the physicochemical properties of NPs (size, shape, charge and targeting ligands) influence NP uptake by TAMs in vitro and in vivo in the TME. Furthermore, we provide a comparative analysis of passive and active NP-based TAM-targeting strategies and discuss their therapeutic potential.

TRAIL Conjugated Silver Nanoparticle Synthesis, Characterization and Therapeutic Effects on HT-29 Colon Cancer Cells

Colon cancer is one of the most prominent causes of cancer-related morbidity and mortality and curable if detected in the early stages. TNF-related apoptosis-inducing ligand (TRAIL) is a therapeutic protein and has a potential anti-cancer activity that is widely used for the treatment of several cancers. In this study, we aimed to develop a silver nanoparticle system conjugated with TRAIL and coated with PEG (AgCTP NPs) to improve the therapeutic effects of colon cancer. AgCTP NPs were characterized by UV spectrum, FTIR and zetasizer. Cytotoxicity, hemolysis assay and apoptotic effects of nanoparticles were investigated using a colon cancer cell line (HT-29) in-vitro. Treatment with AgCTP NPs effectively inhibited proliferation and colony formation of HT-29 cells. The apoptotic effects of nanoparticles on HT-29 cells were determined as Bax, Bcl-2, PARP and clv-PARP protein expression levels using Western blot. Apoptotic proteins were upregulated by AgCTP NPs. In this study, we demonstrated that AgCTP NPs had an anti-cancer effect by activating cell death. Thus, we have confirmed that silver nanoparticles can be selected as a good carrier for TRAIL therapeutic proteins that can be used to treat colon cancer.

Dual Loading of Doxorubicin and Magnetic Iron Oxide into PLA-TPGS Nanoparticles: Design, in vitro Drug Release Kinetics, and Biological Effects on Cancer Cells

The multifunctional nano drug delivery system (MNDDS) has much revolutionized in cancer treatment, aiming to eliminate many disadvantages of conventional formulations. This paper herein proposes and demonstrates MNDDS inspired by poly(lactide)-tocopheryl polyethylene glycol succinate (PLA-TPGS) copolymer co-loaded Doxorubicin and magnetic iron oxide nanoparticles (MIONs) with a 1 : 1 (w/w) optimal ratio. In vitro drug release kinetics of Doxorubicin from this nanosystem fitted best to the Weibull kinetic model and can be described by the classical Fickian diffusion mechanism under acidic pH conditions. The combination of MIONs and Doxorubicin in the PLA-TPGS copolymer has maintained the fluorescence properties of Doxorubicin and good cell penetration, especially inside the nucleus and its vicinity. Moreover, different cell cycle profiles were observed in HeLa cell lines treated with MNDDSs.

Increased Toxicity of Doxorubicin Encapsulated into pH-Responsive Poly(β-Amino Ester)-Functionalized MCM-41 Silica Nanoparticles

BACKGROUND

The encapsulation of anti-cancer drugs in stimulus-sensitive release systems may provide advantages such as enhanced drug toxicity in tumour tissue cells due to increased intracellular drug release. Encapsulation may also improve release in targeted tissue due to the response to a stimulus such as pH, which is lower in the tumour tissue microenvironment. Here, we evaluated the in vitro toxicity of the Drug Doxorubicin (DOX) loaded into a release system based on poly(β-amino ester)- modified MCM-41 silica nanoparticles.

METHODS

The MCM-41-DOX-PbAE release system was obtained by loading DOX into MCM-41 nanoparticles amino-functionalized with 3-aminopropyltriethoxysilane (APTES) and then coated with a pH-responsive poly(β-amino ester) (PbAE). The physicochemical characteristics of the release system were evaluated through TEM, FTIR and TGA. Cytotoxicity assays were performed on the MCM-41- DOX-PbAE system to determine their effects on the inhibition of human MCF-7 breast cancer cell proliferation after 48 h of exposure through crystal violet assay; the investigated systems included MCF-7 cells with MCM-41, PbAE, and MCM-41-PbAE alone. Additionally, the release of DOX and the change in pH in vitro were determined.

RESULTS

The physicochemical characteristics of the synthesized MCM-41-PbAE system were confirmed, including the nanoparticle size, spherical morphology, mesoporous ordered structure, and presence of PbAE on the surface of the MCM-41 nanoparticles. Likewise, we demonstrated that the release of DOX from the MCM-41-DOX-PbAE system promoted an important reduction in MCF-7 cell viability (~ 70%) compared to the values obtained with MCM-41, PbAE, and MCM-41-PbAE, as well as a reduction in the viability under treatment with just DOX (~ 50%).

CONCLUSION

The results suggest that all the components of the release system are biocompatible and that the encapsulation of DOX in MCM-41-PbAE could allow better intracellular release, which would probably increase the availability and toxic effect of DOX.

Nanocarriers Used in Drug Delivery to Enhance Immune System in Cancer Therapy

Cancer, a group of diseases responsible for the second largest cause of global death, is considered one of the main public health problems today. Despite the advances, there are still difficulties in the development of more efficient cancer therapies and fewer adverse effects for the patients. In this context, nanobiotechnology, a materials science on a nanometric scale specified for biology, has been developing and acquiring prominence for the synthesis of nanocarriers that provide a wide surface area in relation to volume, better drug delivery, and a maximization of therapeutic efficiency. Among these carriers, the ones that stand out are those focused on the activation of the immune system. The literature demonstrates the importance of this system for anticancer therapy, given that the best treatment for this disease also activates the immune system to recognize, track, and destroy all remaining tumor cells.

First-in-class and best-in-class dendrimer nanoplatforms from concept to clinic: Lessons learned moving forward

Research to develop active dendrimers by themselves or as nanocarriers represents a promising approach to discover new biologically active entities that can be used to tackle unmet medical needs including difficult diseases. These developments are possible due to the exceptional physicochemical properties of dendrimers, including their biocompatibility, as well as their therapeutic activity as nanocarriers and drugs themselves. Despite a large number of academic studies, very few dendrimers have crossed the 'valley of death' between. Only a few number of pharmaceutical companies have succeeded in this way. In fact, only Starpharma (Australia) and Orpheris, Inc. (USA), an Ashvattha Therapeutics subsidiary, can fill all the clinic requirements to have in the market dendrimers based drugs/nancocarriers. After evaluating the main physicochemical properties related to the respective biological activity of dendrimers classified as first-in-class or best-in-class in nanomedicine, this original review analyzes the advantages and disavantages of these two strategies as well the concerns to step in clinical phases. Various solutions are proposed to advance the use of dendrimers in human health.