Endogenous stimuli-responsive linkers in nanoliposomal systems for cancer drug targeting

Study of the anti-cancer activity of a mesoporous silica nanoparticle surface coated with polydopamine loaded with umbelliprenin

A mesoporous silica nanoparticle (MSN) coated with polydopamine (PDA) and loaded with umbelliprenin (UMB) was prepared and evaluated for its anti-cancer properties in this study. Then UMB-MSN-PDA was characterized by dynamic light scattering (DLS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and FTIR methods. UV-visible spectrometry was employed to study the percentage of encapsulation efficiency (EE%). UMB-MSN-PDA mediated cell cytotoxicity and their ability to induce programmed cell death were evaluated by MTT, real-time qPCR, flow cytometry, and AO/PI double staining methods. The size of UMB-MSN-PDA was 196.7 with a size distribution of 0.21 and a surface charge of -41.07 mV. The EE% was 91.92%. FESEM and TEM showed the spherical morphology of the UMB-MSN-PDA. FTIR also indicated the successful interaction of the UMB and MSN and PDA coating. The release study showed an initial 20% release during the first 24 h of the study and less than 40% during 168 h. The lower cytotoxicity of the UMB-MSN-PDA against HFF normal cells compared to MCF-7 carcinoma cells suggested the safety of formulation on normal cells and tissues. The induction of apoptosis in MCF-7 cells was indicated by the upregulation of P53, caspase 8, and caspase 9 genes, enhanced Sub-G1 phase cells, and the AO/PI fluorescent staining. As a result of these studies, it may be feasible to conduct preclinical studies shortly to evaluate the formulation for its potential use in cancer treatment.

Novel formulation of parthenolide-loaded liposome coated with chitosan and evaluation of its potential anticancer effects in vitro

BACKGROUND

In this study the formulation of parthenolide (PN), an anticancer agent extracted from a natural product, into a liposome (PN-liposome), was examined. The surface of the PN-liposome was modified using chitosan (PN-chitosome). By using real-time quantitative PCR and flow cytometry, we examined the release of PN-chitosomes, cytotoxicity, and ability to induce apoptosis in vitro.

METHODS AND RESULTS

According to the present study, PN-chitosomes had a size of 251 nm which is acceptable for efficient enhanced permeation and retention (EPR) performance. PN-chitosomes were confirmed to be spherical in shape and size through FESEM analysis. In terms of encapsulation efficiency, 94.5% was achieved. PN-chitosome possessed a zeta potential of 34.72 mV, which was suitable for its stability. According to the FTIR spectra of PN and PN-chitosome, PN was chemically stable due to the intermolecular interaction between the liposome and the drug. After 48 h, only 10% of the PN was released from the PN-chitosome in PBS (pH 7.4), and less than 20% was released after 144 h.

CONCLUSION

In a dose-dependent manner, PN-chitosome exhibited anticancer properties that were more cytotoxic against cancer cells than normal cells. Moreover, the formulation activated both the apoptosis pathway and cytotoxic genes in real-time qPCR experiments. According to the cytotoxicity and activating apoptosis of the prepared modified particle, PN-chitosome may be helpful in the treatment of cancer.

In vitro and in vivo study on the anticancer effects of anethole-loaded bovine serum albumin nanoparticles surface decorated with chitosan and folic acid

Anethole (Ant) is a herbal compound with unique properties, which is limited in its clinical use due to its low solubility in aqueous solutions. Therefore, in this study, albumin nanocarrier modified with chitosan-folate was used to transfer Ant to cancer cells and its anticancer effects were evaluated. First, Ant was loaded on albumin nanoparticles by desolvation method and then the surface of nanoparticles was covered with chitosan bound to folate. After characterization, the amount of Ant loading in nanoparticles was measured by the absorption method and then its toxicity effects on breast cancer cell lines, colon, and normal cells were evaluated by the MTT method. The real-time QPCR method was used to investigate the expression changes of apoptosis-related genes in the treated cells compared to the control cells, and finally, the antitumor effects of nanoparticles were evaluated in the mouse model carrying breast cancer. The results of this investigation showed the presence of nanoparticles with dimensions of 252 nm, a dispersion index of 0.28 mV, and a surface charge of 27.14 mV, which are trapped in about 88% of ATL. The toxicity effect of nanoparticles was shown on breast, colon, and normal cancer cells, respectively. In addition, the examination of the gene profile under investigation showed an increase in the expression of BAX and caspase-3 and -9 along with a decrease in the expression of the Bcl-2 gene, which confirms the activation of the internal pathway of apoptosis. The decrease in the volume of tumors and the presence of apoptotic areas in the tissue sections confirmed the antitumor effects of nanoparticles in the in vivo model. The inhibition percentage of free Ant and nanoparticles with a concentration of 25 and 50 mg/kg/tumor volume was reported as 36.9%, 56.6%, and 64.9%, respectively, during 15 days of treatment. These results showed the effectiveness of the formulation in inhibiting cancer cells both in vitro and in vivo.

Endogenous stimuli-responsive drug delivery nanoplatforms for kidney disease therapy

Kidney disease is one of the most life-threatening health problems, affecting millions of people in the world. Commonly used steroids and immunosuppressants often fall exceptionally short of outcomes with inescapable systemic toxicity. With the booming research in nanobiotechnology, stimuli-responsive nanoplatform has come an appealing therapeutic strategy for kidney disease. Endogenous stimuli-responsive materials have shown profuse promise owing to their enhanced spatiotemporal control and precise to the location of the lesion. This review focuses on recent advances stimuli-responsive drug delivery nano-architectonics for kidney disease. First, a brief introduction of pathogenesis of kidney disease and pathological microenvironment were provided. Then, various endogenous stimulus involved in drug delivery nanoplatforms including pH, ROS, enzymes, and glucose were categorized based on the pathological mechanisms of kidney disease. Next, we separately summarized literature examples of endogenous stimuli-responsive nanomaterials, and outlined the design strategies and response mechanisms. Finally, the paper was concluded by discussing remaining challenges and future perspectives of endogenous stimuli-responsive drug delivery nanoplatform for expediting the speed of development and clinical applications.

Synthesis and evaluation of biological effects of modified graphene oxide nanoparticles containing Lawson (Henna extract) on gastric cancer cells

PURPOSE

Targeted Graphene Oxide (GO) nanoparticles can play an important role in the treatment of cancer by increasing cancer cell targeting. This study was conducted to synthesize GO nanoparticles functionalized with chitosan-folate (CS-FA) to deliver a natural product Lawsone (LA) for cancer treatment.

METHODS

After characterization of the LA-GO-CS-FA, antioxidant activities of the nanoparticles were investigated by ABTS, DPPH, and FRAP tests. CAM assay was used to study the effect of nanoparticles on angiogenesis. The expression level of inflammatory and angiogenic genes in cells treated with nanoparticles was evaluated by real-time PCR.

RESULTS

The findings demonstrated the formation of nanoparticles with a size of 113.3 nm, a PDI of 0.31, and a surface charge of + 11.07 mV. The percentages of encapsulation efficiency were reported at 93%. Gastric cancer cells were reported as the most sensitive to treatment compared to the control, and the gastric cancer cells were used to study gene expression changes. The anti-angiogenic effects of nanoparticles were confirmed by reducing the average number and length of blood vessels and reducing the height and weight of embryos in the CAM assay. The reducing the expression of genes involved in angiogenesis in real-time PCR was demonstrated. Nanoparticles displayed high antioxidant properties by inhibiting DPPH and ABTS radicals and reducing iron ions in the FRAP method. The reduction of pro-inflammatory genes in AGS cells which were treated with nanoparticles indicates the anti-inflammatory properties of nanoparticles.

CONCLUSION

This study showed the efficacy of nanoparticles in inhibiting gastric cancer cells by relying on inhibiting angiogenesis.

Stimuli-Responsive Silica Silanol Conjugates: Strategic Nanoarchitectonics in Targeted Drug Delivery

The design of novel drug delivery systems is exceptionally critical in disease treatments. Among the existing drug delivery systems, mesoporous silica nanoparticles (MSNs) have shown profuse promise owing to their structural stability, tunable morphologies/sizes, and ability to load different payload chemistry. Significantly, the presence of surface silanol groups enables functionalization with relevant drugs, imaging, and targeting agents, promoting their utility and popularity among researchers. Stimuli-responsive silanol conjugates have been developed as a novel, more effective way to conjugate, deliver, and release therapeutic drugs on demand and precisely to the selected location. Therefore, it is urgent to summarize the current understanding and the surface silanols' role in making MSN a versatile drug delivery platform. This review provides an analytical understanding of the surface silanols, chemistry, identification methods, and their property-performance correlation. The chemistry involved in converting surface silanols to a stimuli-responsive silica delivery system by endogenous/exogenous stimuli, including pH, redox potential, temperature, and hypoxia, is discussed in depth. Different chemistries for converting surface silanols to stimuli-responsive bonds are discussed in the context of drug delivery. The critical discussion is culminated by outlining the challenges in identifying silanols' role and overcoming the limitations in synthesizing stimuli-responsive mesoporous silica-based drug delivery systems.

Rational Understanding of Loading and Release of Doxorubicin by UV-Light- and pH-Responsive Poly(NIPAM-co-SPMA) Micelle-like Aggregates

A deep understanding of the interactions between micelle-like aggregates and antineoplastic drugs is paramount to control their adequate delivery. Herein, Poly(NIPAM-co-SPMA) copolymer nanocarriers were synthesized according to our previous published methodology, and the loading and release of poorly and highly water-soluble doxorubicin forms (Dox and Dox-HCl, respectively) were evaluated upon UV light irradiation and pH-variation stimuli. Capillary electrophoresis (CE) coupled to a fluorescence detector (LIF) allowed us to specifically characterize these systems and deeply study the loading and release processes. For this purpose, varying concentrations of doxorubicin were tested, and the loading/release rates were indirectly quantified thanks to the "free" doxorubicin concentration in solution. This study highlighted that Dox loading (9.4 μg/mg) was more effective than Dox-HCl loading (5.5 μg/mg). In contrast, 68 and 74% of Dox-HCl were respectively released after 2 min upon pH variation (from 7.4 to 6.0) and combined UV + pH 6.0 stimuli, while only 27% of Dox was invariably released upon application of the same stimuli. These results are coherent with the characteristics of both DoxHCl and Dox: Electrostatic interactions between Dox-HCl and the micelle-membrane structure (NIPAM) seemed predominant, while hydrophobic interactions were expected between Dox and the SP moieties at the inner part of the micelle-like aggregate, leading to different behaviors in both loading and release of the two doxorubicin forms. For doxorubicin loading concentrations higher than 3 μM, the electrophoretic profiles presented an additional peak. Thanks to CE characterizations, this peak was attributed to the formation of a complex formed between the nonaggregated copolymer and the doxorubicin molecules. This report therefore undergoes deep characterization of the dynamic formation of different micelle/drug complexes involved in the global drug-delivery behavior and therefore contributes to the development of more effective stimuli-responsive nanocarriers.

Doxorubicin-loaded liposomes surface engineered with the matrix metalloproteinase-2 cleavable polyethylene glycol conjugate for cancer therapy

Background

Colorectal cancer is one of the prominent leading causes of fatality worldwide. Despite recent advancements within the field of cancer therapy, the cure rates and long-term survivals of patients suffering from colorectal cancer have changed little. The application of conventional chemotherapeutic agents like doxorubicin is limited by some drawbacks such as cardiotoxicity and hematotoxicity. Therefore, nanotechnology has been exploited as a promising solution to address these problems. In this study, we synthesized and compared the anticancer efficacy of doxorubicin-loaded liposomes that were surface engineered with the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-matrix metalloproteinase-2 (MMP-2) cleavable peptide-polyethylene glycol (PEG) conjugate. The peptide linker was used to cleave in response to the upregulated MMP-2 in the tumor microenvironment, thus exposing a positive charge via PEG-deshielding and enhancing liposomal uptake by tumor cells/vasculature. Liposomal formulations were characterized in terms of size, surface charge and morphology, drug loading, release properties, cell binding and uptake, and cytotoxicity.

Results

The formulations had particle sizes of ~ 100-170 nm, narrow distribution (PDI ˂ 0.2), and various surface charges (- 10.2 mV to + 17.6 mV). MMP-2 overexpression was shown in several cancer cell lines (C26, 4T1, and B16F10) as compared to the normal NIH-3T3 fibroblast cells by gelatin zymography and qRT-PCR. In vitro results demonstrated enhanced antitumor efficacy of the PEG-cleavable cationic liposomes (CLs) as compared to the commercial Caelyx^® (up to fivefold) and the chick chorioallantoic membrane assay showed their great antiangiogenesis potential to target and suppress tumor neovascularization. The pharmacokinetics and efficacy studies also indicated higher tumor accumulation and extended survival rates in C26 tumor-bearing mice treated with the MMP-2 cleavable CLs as compared to the non-cleavable CLs with no remarkable sign of toxicity in healthy tissues.

Conclusion

Altogether, the MMP-2-cleavable CLs have great potency to improve tumor-targeted drug delivery and cellular/tumor-vasculature uptake which merits further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12645-023-00169-8.

Nanoparticle-Based Drug Delivery Systems Targeting Tumor Microenvironment for Cancer Immunotherapy Resistance: Current Advances and Applications

Cancer immunotherapy has shown impressive anti-tumor activity in patients with advanced and early-stage malignant tumors, thus improving long-term survival. However, current cancer immunotherapy is limited by barriers such as low tumor specificity, poor response rate, and systemic toxicities, which result in the development of primary, adaptive, or acquired resistance. Immunotherapy resistance has complex mechanisms that depend on the interaction between tumor cells and the tumor microenvironment (TME). Therefore, targeting TME has recently received attention as a feasibility strategy for re-sensitizing resistant neoplastic niches to existing cancer immunotherapy. With the development of nanotechnology, nanoplatforms possess outstanding features, including high loading capacity, tunable porosity, and specific targeting to the desired locus. Therefore, nanoplatforms can significantly improve the effectiveness of immunotherapy while reducing its toxic and side effects on non-target cells that receive intense attention in cancer immunotherapy. This review explores the mechanisms of tumor microenvironment reprogramming in immunotherapy resistance, including TAMs, CAFs, vasculature, and hypoxia. We also examined whether the application of nano-drugs combined with current regimens is improving immunotherapy clinical outcomes in solid tumors.

Tumor microenvironment-responsive size-switchable drug delivery nanosystems

INTRODUCTION

Compared with ordinary chemotherapeutic drugs, the variable-size nanoparticles (NPs) have better therapeutic effects and fewer side effects.

AREAS COVERED

This review mainly summarizes the strategies used to construct smart, size-tunable nanocarriers based on characteristic factors of tumor microenvironment (TME) to dramatically increase the penetration and retention of drugs within tumors.

EXPERT OPINION

Nanosystems with changeable sizes based on the TME have been extensively studied in the past decade, and their permeability and retention have been greatly improved, making them a very promising treatment for tumors.

Redox-sensitive irinotecan liposomes with active ultra-high loading and enhanced intracellular drug release

In this report, a novel irinotecan (IR) encapsulated redox-responsive liposome was developed. The redox-responsive liposomes were prepared based on disulfide phosphatidylcholine (SS-PC), DSPC, DSPE-PEG2000 and cholesterol by ethanol injection method. IR was actively loaded by triethylammonium sucrose octasulfate (TEA8-SOS) gradient method to generate IR/SS-PC liposomes (IR/SS-LP). The particle size of IR/SS-PC was characterized by using dynamic light scattering (DLS) and transmission electron microscopy (TEM). It was found that IR/SS-LP with 30 % content of SS-PC (IR/SS30-LP) had an average size of 125.5 ± 5.8 nm with a negative zeta potential of -19.5 ± 0.1. The encapsulation efficiency (EE) was further determined to be 98.1 ± 0.8 % and drug loading (DL) was 31.8 ± 0.1 %. The redox-responsiveness of IR/SS-LP was investigated by observing the change of particle size and morphology as well as the release behavior of IR triggered by glutathione (GSH). The data indicated GSH breaks the disulfide bonds in SS-PC and leads to the controlled release of IR. At 1 mM GSH, 60.2 % irinotecan was released from IR/SS30-LP within 24 h. Finally, the effects of IR/SS-LP in cell and animal experiments were evaluated in detail. The results showed that IR/SS30-LP had superior pharmacokinetic and antitumor efficacy compared to free irinotecan and traditional irinotecan liposome (ONIVYDE®-like). Taken together, IR/SS30-LP displayed redox-responsive release of IR, ultra-high loading and enhanced anti-tumor activity, which has great potential for clinical application as a new generation of IR liposomal formulation.

Improving anti-tumour efficacy of PEGylated liposomal doxorubicin by dual targeting of tumour cells and tumour endothelial cells using anti-p32 CGKRK peptide

The aim of this study was to surface-functionalize PEGylated liposomal doxorubicin (PLD) using anti-p32 CGKRK peptide to evaluate its anti-angiogenic and anti-tumour activities. CGKRK was conjugated to DSPE-mPEG₂₀₀₀-maleimide and post-inserted into PLD at 25, 50, 100, 200 and 400 peptides per each liposome and characterised for their size, zeta potential, drug loading, release properties; and cell binding, cell uptake and cytotoxicity on three C26, 4T1 and human umbilical vein endothelial cell (HUVEC) cell lines. The in vitro results indicated the better efficiency of the PLD-100 (PLD with 100 CGKRK) formulation on 4T1 and HUVEC cell lines. The results of anti-tube formation and spheroid assay indicated the efficiencies of the PLD-100 formulation compared with Caelyx^® in vitro. The in vivo studies indicated the higher tumour accumulation of PLD-100 formulation in comparison with Caelyx^® which also implied the higher survival rates in mice treated with PLD-100 formulation. Histological evaluations demonstrated that PLD-100 had no side-effects on major organs. In conclusion, the results of this study indicated that PLD-CGKRK- could efficiently target endothelial and tumour parenchymal cells which enhance the therapeutic efficacy of PLD and merits further investigation.

Stimuli-Responsive Iron Oxide Nanotheranostics: A Versatile and Powerful Approach for Cancer Therapy

Recent advancements in unravelling elements of cancer biology involved in disease progression and treatment resistance have highlighted the need for a holistic approach to effectively tackle cancer. Stimuli-responsive nanotheranostics based on iron oxide nanoparticles are an emerging class of versatile nanomedicines with powerful capabilities to "seek, sense, and attack" multiple components of solid tumors. In this work, the rationale for using iron oxide nanoparticles and the basic physical principles that impact their function in biomedical applications are reviewed. Subsequently, recent advances in the integration of iron oxide nanoparticles with various stimulus mechanisms to facilitate the development of stimuli-responsive nanotheranostics for application in cancer therapy are summarized. The integration of an iron oxide core with various surface coating mechanisms results in the generation of hybrid nanoconstructs with capabilities to codeliver a wide variety of highly potent anticancer therapeutics and immune modulators. Finally, emerging future directions and considerations for their clinical translation are touched upon.

Preparation of liposomes containing IFN-gamma and their potentials in cancer immunotherapy: In vitro and in vivo studies in a colon cancer mouse model

The purpose of this study was to prepare non-PEGylated (HSPC/DSPG/Chol, LIPF1) and PEGylated (HSPC/DSPG/Chol/mPEG2000-DSPE, LIPF2) liposomal formulations containing Interferon-gamma (IFN-γ) and evaluation their effects on macrophages and their antitumor properties. The results showed that the size of liposomal formulations LIP-F1 and LIP-F2 was 120 and 135 nm, respectively. The encapsulation efficiencies of LIP-F1 and LIP-F2 were 52.79% and 49.2%, respectively. Nitric Oxide Synthase (INOS) and arginase assays showed an increase in nitric oxide (NO) level and a reduction in arginase level after the treatment of M2 phenotype macrophage cell line with IFN-γ liposomes. The biodistribution study illustrated the amplitude of iodinated-IFN-γ liposomal formulations in the tumor site, the circulation time and tumor accumulation of LIP-F2 was significantly more than LIPF1. As a result, PEGylated liposomes containing IFN-γ induced significant antitumor responses due to the increased delivery of the cargo to the immune cells and induction of antitumor immune responses.

Anti-Epcam Aptamer (Syl3c)-Functionalized Liposome for Targeted Delivery Of Doxorubicin: In Vitro And In Vivo Antitumor Studies in Mice Bearing C26 Colon Carcinoma

In this study, we have surface-functionalized PEGylated-nanoliposomal doxorubicin (DOX) with anti-EpCAM (epithelial cell adhesion molecule) aptamer via post-insertion of anti-EpCAM aptamer-conjugated DSPE-mPEG₂₀₀₀ into Caelyx® (ED-lip). The size, charge, release profile, and cytotoxicity and cellular uptake of formulation were determined. The characterization of the ED-lip demonstrated the slightly increase in size and PDI along with the decrease in zeta potential which indicated that post-insertion efficiently done. The results of flow cytometry and fluorescent microscopy have shown that ED-lip enhanced the rate of cell uptake on C26 cell line compared to Caelyx®. The ED-lip also had more cytotoxic effects than Caelyx® which indicated the efficacy of anti-EpCAM aptamer as targeting ligand. The pharmacokinetic and tissue biodistribution of formulations in mice bearing C26 tumors demonstrated that ED-lip did not affect the distribution profile of DOX compared to Caelyx® in animal model. In addition, ED-lip effectively improved the tumor accumulation of DOX and promoted survival of animals compared to Caelyx®. These results suggest that the functionalization of Caelyx® with anti-EpCAM aptamer is promising in cancer treatment and merits further investigation.

Hypoxia-activated nanomedicines for effective cancer therapy

Hypoxia, a common characteristic in solid tumors, is found in phenotypically aggressive cancers that display resistance to typical cancer interventions. Due to its important role in tumor progression, tumor hypoxia has been considered as a primary target for cancer diagnosis and treatment. An advantage of hypoxia-activated nanomedicines is that they are inactive in normoxic cells. In hypoxic tumor tissues and cells, these nanomedicines undergo reduction by activated enzymes (usually through 1 or 2 electron oxidoreductases) to produce cytotoxic substances. In this review, we will focus on approaches to design nanomedicines that take advantage of tumor hypoxia. These approaches include: i) inhibitors of hypoxia-associated signaling pathways; ii) prodrugs activated by hypoxia; iii) nanocarriers responsive to hypoxia, and iv) bacteria mediated hypoxia targeting therapy. These strategies have guided and will continue to guide nanoparticle design in the near future. These strategies have the potential to overcome tumor heterogeneity to improve the efficiency of radiotherapy, chemotherapy and diagnosis.