Improving conventional enhanced permeability and retention (EPR) effects; what is the appropriate target?

Monomethyl Auristatin E Grafted-Liposomes to Target Prostate Tumor Cell Lines

Novel nanomedicines have been engineered to deliver molecules with therapeutic potentials, overcoming drawbacks such as poor solubility, toxicity or short half-life. Lipid-based carriers such as liposomes represent one of the most advanced classes of drug delivery systems. A Monomethyl Auristatin E (MMAE) warhead was grafted on a lipid derivative and integrated in fusogenic liposomes, following the model of antibody drug conjugates. By modulating the liposome composition, we designed a set of particles characterized by different membrane fluidities as a key parameter to obtain selective uptake from fibroblast or prostate tumor cells. Only the fluid liposomes made of palmitoyl-oleoyl-phosphatidylcholine and dioleoyl-phosphatidylethanolamine, integrating the MMAE-lipid derivative, showed an effect on prostate tumor PC-3 and LNCaP cell viability. On the other hand, they exhibited negligible effects on the fibroblast NIH-3T3 cells, which only interacted with rigid liposomes. Therefore, fluid liposomes grafted with MMAE represent an interesting example of drug carriers, as they can be easily engineered to promote liposome fusion with the target membrane and ensure drug selectivity.

Preparation and in vitro/vivo evaluation of folate-conjugated pluronic F87-PLGA/TPGS mixed nanoparticles for targeted drug delivery

AIM

Folate-conjugated Pluronic F87-poly(lactic-co-glycolic acid) block copolymer (FA-F87-PLGA) was synthesized to encapsulate anticancer drug Paclitaxel (PTX) for targeted drug delivery. To further improve the curative effect, D-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS or Vitamin E TPGS) was added to form FA-F87-PLGA/TPGS mixed NPs.

METHODS

FA-F87-PLGA was synthesized by the ring-opening polymerization and the structure was characterized. PTX-loaded nanoparticles were prepared with the nanoprecipitation method. The physicochemical characteristics were studied to determine the appropriate dose ratio of the FA-F87-PLGA to TPGS. The cytotoxicity against Ovarian Cancer Cells (OVCAR-3) was determined by MTT assay. The Area-Under-the Curve (AUC) and half-life were measured in the vivo pharmacokinetic studies.

RESULTS

Based on the optimization of particle size and embedding rate of PTX-loaded mixed NPs, the appropriate dosage ratio of FA-F87-PLGA to TPGS was finally determined to be 5:3. According to in vitro release studies, the cumulative release rate of PTX-loaded FA-F87-PLGA/TPGS mixed NPs was 92.04%, which was higher than that of nanoparticles without TPGS. The cytotoxicity studies showed that the IC50 value of PTX-loaded FA-F87-PLGA/TPGS decreased by 75.4 times and 19.7 times after 72 h treatment compared with free PTX injections and PTX-loaded FA-F87-PLGA NPs, respectively. In vivo pharmacokinetic studies indicated that FA-F87-PLGA/TPGS mixed NPs had a longer drug metabolism time and a larger Area-Under-the-Curve (AUC) compared with free PTX injections.

CONCLUSION

FA-F87-PLGA/TPGS mixed NPs are potential candidates for targeted drug delivery systems.

Amelioration of Tumor Targeting and In Vivo Biodistribution of 99mTc-Methotrexate-Gold Nanoparticles (99mTc-Mex-AuNPs)

Gold nanoparticles (AuNPs) represent very attractive and promising drug delivery carriers due to their unique dimensions, adjustable surface functions, and controllable drug release. Therefore, AuNPs are used to overcome the limitations of conventional chemotherapy, for example methotrexate (Mex), one of the first-generation chemotherapy drugs for cancer treatment, whose usefulness has been restricted due to drug resistance and dose-dependent side effects. In the present study, the AuNPs drug delivery system was synthesized and loaded with technetium-99 m radiolabeled Methotrexate (^99mTc-Mex) to produce new potential nanoradiopharmaceutical for tumor targeting and further imaging. The Methotrexate loaded gold nanoparticles (Mex-AuNPs) successfully prepared in small spherical particle size (20.3 nm), polydispersity index PDI (< 0.5) and a zeta potential (-17.6 mV) with loading efficiency% (93 ± 1.2%) of methotrexate at 30 min as an optimum stirring time and showed strong absorption peak for Mex-AuNPs at λ_max, 525 nm. The in vitro release profile of Mex-AuNPs showed high release percent of methotrexate at pH 5; the Q_0.5 h and Q_8h were 21.2 ± 1.5% and 92.9 ± 3.4%, respectively. The in vitro cytotoxicity was investigated at different concentrations (0.024-50 μl/100 μl) of Mex-AuNPs (1 mg/ml) against MCF-7 (Michigan Cancer Foundation-7) breast cancer cells by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay technique. Mex-AuNPs showed higher anticancer activity with low inhibitory concentration (IC₅₀ = 0.098 μl/100 μl) that was three times lower than the inhibitory concentration (IC₅₀) of methotrexate (IC₅₀ = 0.3 μl/100 μl). ^99mTc-Mex complex prepared by direct reduction method at maximum radiochemical yield (RCY)% ̴ 98.3 ± 1.09 % was loaded in AuNPs to form ^99mTc-Mex-AuNPs with loading efficiency% (93 ± 1.2 %) at 30 min of stirring time. ^99mTc-Mex-AuNPs showed convenient in vitro stability in mice serum up to 24 h with RCY% > 90 %. The preclinical biodistribution studies of ^99mTc-Mex-AuNPs were performed in 3 experimental groups A (intravenous (I.V.) injected normal mice), B and C (I.V. and intratumor (I.T.) injected tumor bearing mice, respectively). The ^99mTc-Mex-AuNPs achieved highest tumor uptake (93 ± 0.39 %ID/g) and highest Target/NonTarget (T/NT) ratio (58.1 ± 0.91) with high Tumor/Blood (T/B) ratio (25.8 ± 0.11) at 10 min post I.T. injection and retained high tumor uptake (79 ± 0.65 %ID/g) up to 60 min post I.T. injection before escaping into blood stream. Consequently, ^99mTc-Mex-AuNPs can be considered as new potential nanoradiopharmaceutical in tumor diagnosis.

Cell-Derived Nanovesicles as Exosome-Mimetics for Drug Delivery Purposes: Uses and Recommendations

Cell-derived Drug Delivery Systems (DDSs), particularly exosomes, have grown in popularity and have been increasingly explored as novel DDSs, due to their intrinsic targeting capabilities. However, clinical translation of exosomes is impeded by the tedious isolation procedures and poor yield. Cell-derived nanovesicles (CDNs) have recently been produced and proposed as exosome-mimetics. Various methods for producing exosome-mimetics have been developed. In this chapter, we present a simple, efficient, and cost-effective CDNs production method that uses common laboratory equipment (microcentrifuge) and spin cups. Through a series of extrusion and size exclusion steps, CDNs are produced from in vitro cell culture and are found to highly resemble the endogenous exosomes. Thus, we envision that this strategy holds great potential as a viable alternative to exosomes in the development of ideal DDS.

Electromagnetically Stimuli-Responsive Nanoparticles-Based Systems for Biomedical Applications: Recent Advances and Future Perspectives

Nanoparticles (NPs) in the biomedical field are known for many decades as carriers for drugs that are used to overcome biological barriers and reduce drug doses to be administrated. Some types of NPs can interact with external stimuli, such as electromagnetic radiations, promoting interesting effects (e.g., hyperthermia) or even modifying the interactions between electromagnetic field and the biological system (e.g., electroporation). For these reasons, at present these nanomaterial applications are intensively studied, especially for drugs that manifest relevant side effects, for which it is necessary to find alternatives in order to reduce the effective dose. In this review, the main electromagnetic-induced effects are deeply analyzed, with a particular focus on the activation of hyperthermia and electroporation phenomena, showing the enhanced biological performance resulting from an engineered/tailored design of the nanoparticle characteristics. Moreover, the possibility of integrating these nanofillers in polymeric matrices (e.g., electrospun membranes) is described and discussed in light of promising applications resulting from new transdermal drug delivery systems with controllable morphology and release kinetics controlled by a suitable stimulation of the interacting systems (nanofiller and interacting cells).

Fe3O4-Au Core-Shell Nanoparticles as a Multimodal Platform for In Vivo Imaging and Focused Photothermal Therapy

In this study, we report the synthesis of gold-coated iron oxide nanoparticles capped with polyvinylpyrrolidone (Fe@Au NPs). The as-synthesized nanoparticles (NPs) exhibited good stability in aqueous media and excellent features as contrast agents (CA) for both magnetic resonance imaging (MRI) and X-ray computed tomography (CT). Additionally, due to the presence of the local surface plasmon resonances of gold, the NPs showed exploitable "light-to-heat" conversion ability in the near-infrared (NIR) region, a key attribute for effective photothermal therapies (PTT). In vitro experiments revealed biocompatibility as well as excellent efficiency in killing glioblastoma cells via PTT. The in vivo nontoxicity of the NPs was demonstrated using zebrafish embryos as an intermediate step between cells and rodent models. To warrant that an effective therapeutic dose was achieved inside the tumor, both intratumoral and intravenous routes were screened in rodent models by MRI and CT. The pharmacokinetics and biodistribution confirmed the multimodal imaging CA capabilities of the Fe@AuNPs and revealed constraints of the intravenous route for tumor targeting, dictating intratumoral administration for therapeutic applications. Finally, Fe@Au NPs were successfully used for an in vivo proof of concept of imaging-guided focused PTT against glioblastoma multiforme in a mouse model.

Hybrid Nanoparticles Modified by Hyaluronic Acid Loading an HSP90 Inhibitor as a Novel Delivery System for Subcutaneous and Orthotopic Colon Cancer Therapy

Background

As a therapeutic target for cancer treatment, HSP90 has been explored extensively. However, the significant side effects of the HSP90 inhibitor 17AAG have limited its clinical use.

Methods

In this study, we used hyaluronic acid (HA)–decorated DOTAP–PLGA hybrid nanoparticles (HA-DOTAP-PLGA NPs) as 17AAG-delivery carriers for targeted colon cancer therapy.

Results

Different methods were used to characterize the successful fabrication of these hybrid PLGA NPs. Our results demonstrated that internalization of HA-NPs in colon cancer cells was governed by CD44receptor–mediated endocytosis. Annexin V–propidium iodide staining experiments revealed that cell apoptosis induced by HA-NPs-17AAG in colon cancer cells was more efficient than free 17AAG. In two animal models used to screen anticancer efficacy (Luc-HT29 subcutaneous xenograft and AOM/DSS-induced orthotopic tumor model), HA-NPs-17AAG significantly inhibited xenograft and orthotopic tumor growth, demonstrating HA-NPs-17AAG had much better therapeutic efficiency than free 17AAG. It is worth noting that great biocompatibility of HA-DOTAP-PLGA NPs was observed both in vitro and in vivo.

Conclusion

Our research offers a preclinical proof of concept for colon cancer therapy with DOTAP-PLGA NPs as a creative drug-delivery system.

Improved pentamethine cyanine nanosensors for optoacoustic imaging of pancreatic cancer

Optoacoustic imaging is a new biomedical imaging technology with clear benefits over traditional optical imaging and ultrasound. While the imaging technology has improved since its initial development, the creation of dedicated contrast agents for optoacoustic imaging has been stagnant. Current exploration of contrast agents has been limited to standard commercial dyes that have already been established in optical imaging applications. While some of these compounds have demonstrated utility in optoacoustic imaging, they are far from optimal and there is a need for contrast agents with tailored optoacoustic properties. The synthesis, encapsulation within tumor targeting silica nanoparticles and applications in in vivo tumor imaging of optoacoustic contrast agents are reported.

Bioactive Polymeric Materials for the Advancement of Regenerative Medicine

Biopolymers are widely accepted natural materials in regenerative medicine, and further development of their bioactivities and discoveries on their composition/function relationships could greatly advance the field. However, a concise insight on commonly investigated biopolymers, their current applications and outlook of their modifications for multibioactivity are scarce. This review bridges this gap for professionals and especially freshmen in the field who are also interested in modification methods not yet in commercial use. A series of polymeric materials in research and development uses are presented as well as challenges that limit their efficacy in tissue regeneration are discussed. Finally, their roles in the regeneration of select tissues including the skin, bone, cartilage, and tendon are highlighted along with modifiable biopolymer moieties for different bioactivities.

Novel Complex of PD-L1 Aptamer and Holliday Junction Enhances Antitumor Efficacy in Vivo

Blocking the PD-1/PD-L1 pathway can diminish immunosuppression and enhance anticancer immunity. PD-1/PD-L1 blockade can be realized by aptamers, which have good biocompatibility and can be synthesized in quantity economically. For in vivo applications, aptamers need to evade renal clearance and nuclease digestion. Here we investigated whether DNA nanostructures could be used to enhance the function of PD-L1 aptamers. Four PD-L1 aptamers (Apt) were built into a Holliday Junction (HJ) to form a tetravalent DNA nanostructure (Apt-HJ). The average size of Apt-HJ was 13.22 nm, which was above the threshold for renal clearance. Apt-HJ also underwent partial phosphorothioate modification and had improved nuclease resistance. Compared with the monovalent PD-L1 aptamer, the tetravalent Apt-HJ had stronger affinity to CT26 colon cancer cells. Moreover, Apt-HJ markedly boosted the antitumor efficacy in vivo vs. free PD-L1 aptamers without raising systemic toxicity. The results indicate that multiple aptamers attached to a DNA nanostructure may significantly improve the function of PD-L1 aptamers in vivo.

Polycationic cyclodextrin nanoparticles induce apoptosis and affect antitumoral activity in HepG2 cell line: An evaluation at the molecular level

Hepatocellular carcinoma (HCC) is a highly metastatic primary liver cancer generating molecular alterations that end up escaping the apoptotic machinery and conferring multidrug resistance. Targeted medicines with increased and selective cytotoxicity and minimal drug resistance are essential for the treatment of HCC. In this study, a self-assembled polycationic (PC) amphiphilic β-cyclodextrin (βCDC6) nanoparticle formulation was characterized and its efficacy over HCC cell line HepG2 was evaluated in terms of cytotoxicity, apoptotic potential, chemosensitivity and mitochondrial balance utilizing biochemical, gene expression and proteomic approaches without encapsulating an anti-neoplastic agent. Blank PC βCDC6 exerted an anti-proliferative effect on 3D multicellular HepG2 spheroid tumors. These nanoparticles were able to trigger apoptosis proved by caspase 3/7 activity, gene expression and flow cytometry studies. The subjection of PC restored the chemosensitivity of HepG2 cells by suppressing the function of p-glycoprotein. The proteomic studies with Q-TOF LC/MS revealed 73 proteins that are aberrantly encoded after cells were treated with the blank PC. Metabolomic analysis further confirmed the shift in certain biological pathways. Thus, we confirmed that the hepatocellular carcinoma-targeting βCDC6 PC nanoparticles induce apoptosis, lower the rate of cell proliferation, hinder multidrug resistance and they are convenient carriers for eventual therapeutic administrations in HCC patients.

Development of thermosensitive resiquimod-loaded liposomes for enhanced cancer immunotherapy

Resiquimod (R848) is a toll-like receptor 7 and 8 (TLR7/8) agonist with potent antitumor and immunostimulatory activity. However, systemic delivery of R848 is poorly tolerated because of its poor solubility in water and systemic immune activation. In order to address these limitations, we developed an intravenously-injectable formulation with R848 using thermosensitive liposomes (TSLs) as a delivery vehicle. R848 was remotely loaded into TSLs composed of DPPC: DSPC: DSPE-PEG2K (85:10:5, mol%) with 100 mM FeSO4 as the trapping agent inside. The final R848 to lipid ratio of the optimized R848-loaded TSLs (R848-TSLs) was 0.09 (w/w), 10-fold higher than the previously-reported values. R848-TSLs released 80% of R848 within 5 min at 42 °C. These TSLs were then combined with αPD-1, an immune checkpoint inhibitor, and ultrasound-mediated hyperthermia in a neu deletion (NDL) mouse mammary carcinoma model (Her2+, ER/PR negative). Combined with αPD-1, local injection of R848-TSLs showed superior efficacy with complete NDL tumor regression in both treated and abscopal sites achieved in 8 of 11 tumor bearing mice over 100 days. Immunohistochemistry confirmed enhanced CD8+ T cell infiltration and accumulation by R848-TSLs. Systemic delivery of R848-TSLs, combined with local hyperthermia and αPD-1, inhibited tumor growth and extended median survival from 28 days (non-treatment control) to 94 days. Upon re-challenge with reinjection of tumor cells, none of the previously cured mice developed tumors, as compared with 100% of age-matched control mice. The dose of R848 (10 μg for intra-tumoral injection or 6 mg/kg for intravenous injection delivered up to 4 times) was well-tolerated without weight loss or organ hypertrophy. In summary, we developed R848-TSLs that can be administered locally or systematically, resulting in tumor regression and enhanced survival when combined with αPD-1 in mouse models of breast cancer.

Viral Nanoparticle System: An Effective Platform for Photodynamic Therapy

Photodynamic therapy (PDT) is a promising therapy due to its efficiency and accuracy. The photosensitizer is delivered to the target lesion and locally activated. Viral nanoparticles (VNPs) have been explored as delivery vehicles for PDT in recent years because of their favorable properties, including simple manufacture and good safety profile. They have great potential as drug delivery carriers in medicine. Here, we review the development of PDT photosensitizers and discuss applications of VNP-mediated photodynamic therapies and the performance of VNPs in the treatment of tumor cells and antimicrobial therapy. Furthermore, future perspectives are discussed for further developing novel viral nanocarriers or improving existing viral vectors.

Nanomaterials for Antiangiogenic Therapies for Cancer: A Promising Tool for Personalized Medicine

Angiogenesis is one of the hallmarks of cancer. Several studies have shown that vascular endothelium growth factor (VEGF) plays a leading role in angiogenesis progression. Antiangiogenic medication has gained substantial recognition and is commonly administered in many forms of human cancer, leading to a rising interest in cancer therapy. However, this treatment method can lead to a deteriorating outcome of resistance, invasion, distant metastasis, and overall survival relative to its cytotoxicity. Furthermore, there are significant obstacles in tracking the efficacy of antiangiogenic treatments by incorporating positive biomarkers into clinical settings. These shortcomings underline the essential need to identify additional angiogenic inhibitors that target numerous angiogenic factors or to develop a new method for drug delivery of current inhibitors. The great benefits of nanoparticles are their potential, based on their specific properties, to be effective mechanisms that concentrate on the biological system and control various important functions. Among various therapeutic approaches, nanotechnology has emerged as a new strategy for treating different cancer types. This article attempts to demonstrate the huge potential for targeted nanoparticles and their molecular imaging applications. Notably, several nanoparticles have been developed and engineered to demonstrate antiangiogenic features. This nanomedicine could effectively treat a number of cancers using antiangiogenic therapies as an alternative approach. We also discuss the latest antiangiogenic and nanotherapeutic strategies and highlight tumor vessels and their microenvironments.

Expanding the Limits of Photodynamic Therapy: The Design of Organelles and Hypoxia-Targeting Nanomaterials for Enhanced Photokilling of Cancer

Photodynamic therapy (PDT) is a minimally invasive clinical protocol that combines a nontoxic photosensitizer (PS), appropriate visible light, and molecular oxygen for cancer treatment. This triad generates reactive oxygen species (ROS) in situ, leading to different cell death pathways and limiting the arrival of nutrients by irreversible destruction of the tumor vascular system. Despite the number of formulations and applications available, the advancement of therapy is hindered by some characteristics such as the hypoxic condition of solid tumors and the limited energy density (light fluence) that reaches the target. As a result, the use of PDT as a definitive monotherapy for cancer is generally restricted to pretumor lesions or neoplastic tissue of approximately 1 cm in size. To expand this limitation, researchers have synthesized functional nanoparticles (NPs) capable of carrying classical photosensitizers with self-supplying oxygen as well as targeting specific organelles such as mitochondria and lysosomes. This has improved outcomes in vitro and in vivo. This review highlights the basis of PDT, many of the most commonly used strategies of functionalization of smart NPs, and their potential to break the current limits of the classical protocol of PDT against cancer. The application and future perspectives of the multifunctional nanoparticles in PDT are also discussed in some detail.

Current Limitations and Recent Progress in Nanomedicine for Clinically Available Photodynamic Therapy

Photodynamic therapy (PDT) using oxygen, light, and photosensitizers has been receiving great attention, because it has potential for making up for the weakness of the existing therapies such as surgery, radiation therapy, and chemotherapy. It has been mainly used to treat cancer, and clinical tests for second-generation photosensitizers with improved physicochemical properties, pharmacokinetic profiles, or singlet oxygen quantum yield have been conducted. Progress is also being made in cancer theranostics by using fluorescent signals generated by photosensitizers. In order to obtain the effective cytotoxic effects on the target cells and prevent off-target side effects, photosensitizers need to be localized to the target tissue. The use of nanocarriers combined with photosensitizers can enhance accumulation of photosensitizers in the tumor site, owing to preferential extravasation of nanoparticles into the tumor vasculature by the enhanced permeability and retention effect. Self-assembly of amphiphilic polymers provide good loading efficiency and sustained release of hydrophobic photosensitizers. In addition, prodrug nanomedicines for PDT can be activated by stimuli in the tumor site. In this review, we introduce current limitations and recent progress in nanomedicine for PDT and discuss the expected future direction of research.

Acid-Responsive Adamantane-Cored Amphiphilic Block Polymers as Platforms for Drug Delivery

Four-arm star-shaped (denoted as ‘S’) polymer adamantane-[poly(lactic-co-glycolic acid)-b-poly(N,N’-diethylaminoethyl methacrylate) poly(ethylene glycol) monomethyl ether]₄ (S-PLGA-D-P) and its linear (denoted as ‘L’) counterpart (L-PLGA-D-P) were synthesized, then their self-assembled micelles were further developed to be platforms for anticancer drug delivery. Two types of polymeric micelles exhibited strong pH-responsiveness and good drug loading capacity (21.6% for S-PLGA-D-P and 22.9% for L-PLGA-D-P). Using doxorubicin (DOX) as the model drug, their DOX-loaded micelles displayed well controlled drug release behavior (18.5–19.0% of DOX release at pH 7.4 and 77.6–78.8% of DOX release at pH 5.0 within 80 h), good cytocompatibility against NIH-3T3 cells and effective anticancer efficacy against MCF-7 cells. However, the star-shaped polymeric micelles exhibited preferable stability, which was confirmed by the lower critical micelle concentration (CMC 0.0034 mg/mL) and decrease rate of particle sizes after 7 days incubation (3.5%), compared with the linear polymeric micelle L-PLGA-D-P (CMC 0.0070 mg/mL, decrease rate of particle sizes was 9.6%). Overall, these developed polymeric micelles have promising application as drug delivery system in cancer therapy.

Immunomodulatory potential of anticancer therapy composed of methotrexate nanoconjugate and dendritic cell‑based vaccines in murine colon carcinoma

Chemotherapy with low-molecular weight compounds, despite elimination of cancer cells, entails adverse effects. To overcome this disadvantage, innovative drug delivery systems are being developed, including conjugation of macromolecular carriers with therapeutics, e.g. a nanoconjugate of hydroxyethyl starch and methotrexate (HES-MTX). The purpose of the present study was to determine whether HES-MTX, applied as a chemotherapeutic, is able to modulate the immune response and support the antitumor response generated by dendritic cells (DCs) used subsequently as immunotherapeutic vaccines. Therefore, MTX or HES-MTX was administered, as sole treatment or combined with DC-based vaccines, to MC38 colon carcinoma tumor-bearing mice. Alterations in antitumor immune response were evaluated by multiparameter flow cytometry analyses and functional assays. The results demonstrated that the nanoconjugate possesses greater immunomodulatory potential than MTX as reflected by changes in the landscape of immune cells infiltrating the tumor and increased cytotoxicity of splenic lymphocytes. In contrast to MTX, therapy with HES-MTX as sole treatment or combined with DC-based vaccines, contributed to significant tumor growth inhibition. However, only treatment with HES-MTX and DC-based vaccines activated the systemic specific antitumor response. In conclusion, due to its immunomodulatory properties, the HES-MTX nanoconjugate could become a potent anticancer agent used in both chemo- and chemoimmunotherapeutic treatment schemes.

Peptide-functionalized liposomes as therapeutic and diagnostic tools for cancer treatment

Clinically efficacious medication in anticancer therapy has been successfully designed with liposome-based nanomedicine. The liposomal formulation in cancer drug delivery can be facilitated with a functionalized peptide that mediates the specific drug delivery opportunities with increased drug penetrability, specific accumulation in the targeted site, and enhanced therapeutic efficacy. This review aims to focus on recent advances in peptide-functionalized liposomal formulation techniques in cancer diagnosis and treatment regarding recently published literature. It also will highlight different aspects of novel liposomal formulation techniques that incorporate surface functionalization with peptides for better anticancer effect and current challenges in peptide-functionalized liposomal drug formulation.

Proniosomal Gel for Topical Delivery of Rutin: Preparation, Physicochemical Characterization and In Vitro Toxicological Profile Using 3D Reconstructed Human Epidermis Tissue and 2D Cells

Rutin (Rut) is a natural flavonol, well-known for its broad-spectrum of therapeutic effects, including antioxidant and antitumoral activities; still, it has a reduced clinical outcome due to its limited solubility in aqueous solutions. To overcome this drawback, this study proposes a novel formulation for rutin as a proniosomal gel for cutaneous applications. The gel was prepared by coacervation phase-separation method and complies with the standard requirements in terms of particle size (140.5 ± 2.56 nm), zeta potential (−27.33 ± 0.09 mV), encapsulation capacity (> 50%), pH (7.002 ± 0.18) and rheological properties. The results showed high biocompatibility of the gel on the 3D reconstructed human epidermis model characterized by increased viability of the cells and a lack of irritant and phototoxic potential. The evaluations on 2D cells confirm the preferential cytotoxic effect of Rut on melanoma cells (IC₅₀ value = 8.601 µM, nuclear fragmentation) compared to normal keratinocytes. Our data suggest that the proniosomal gel is a promising drug carrier for Rut in the management and prevention of skin disorders.

Resilin-mimetics as a smart biomaterial platform for biomedical applications

Intrinsically disordered proteins have dramatically changed the structure-function paradigm of proteins in the 21st century. Resilin is a native elastic insect protein, which features intrinsically disordered structure, unusual multi-stimuli responsiveness and outstanding resilience. Advances in computational techniques, polypeptide synthesis methods and modular protein engineering routines have led to the development of novel resilin-like polypeptides (RLPs) including modular RLPs, expanding their applications in tissue engineering, drug delivery, bioimaging, biosensors, catalysis and bioelectronics. However, how the responsive behaviour of RLPs is encoded in the amino acid sequence level remains elusive. This review summarises the milestones of RLPs, and discusses the development of modular RLP-based biomaterials, their current applications, challenges and future perspectives. A perspective of future research is that sequence and responsiveness profiling of RLPs can provide a new platform for the design and development of new modular RLP-based biomaterials with programmable structure, properties and functions.

A mechanistic insight into benefits of aggregation induced emissive luminogens in cancer

Exploration of advanced chemotheranostics that benefit from a combined in vivo strategy of cancer diagnosis and chemotherapy simultaneously is highly valued and will expose novel possibilities in modifying treatment and reduce side effects. In recent years, nanodrug delivery systems that incorporate aggregation-induced emissive luminogens (AIEgens) have been developed to track and monitor anticancer drug release, trace translocation processes and predict chemotherapeutic responses. There are several classes of AIEgen based chemotheranostics such us stimuli-responsive nanoprodrugs, pH-sensitive mesoporous silica nanocarriers, supramolecular polymer systems, drug encapsulated carriers, carrier-free nanodrugs, self-indicating drug delivery nanomachines and AIEgen-prodrug co-assembly. The present review conveys mechanistic insight into the benefits of AIEgens in the theranostic application by illustrating the recent breakthroughs in chemotheranostic nanomedicines that incorporate these unique fluorophores as signal reporters. The perspectives that can be further explored are also highlighted with the hope to instil more research interest in the advancement of AIE active cancer chemotheranostics for imaging and treatment in vivo.HIGHLIGHTSAggregation induced emissive materials (AIEgens) exhibit unique advantages over conventional luminogens for synergistic diagnosis and chemotherapy of cancer in vivo.The combination of AIE and nanotechnology offers an excellent platform to fabricate advanced chemotheranostics for cancer therapy.

Radiosensitization by Au-nanofilm at micrometer level using confocal Raman spectroscopy

PURPOSE

To measure the radiosensitization by an Au-nanofilm (GNF) at a micrometer level on a radiochromic film (RCF) using confocal Raman spectroscopy (CRS).

METHODS

Unlaminated radiochromic films were irradiated by 200 kVp x-ray from 0.3 to 50 Gy to obtain a calibration curve. Raman spectra of these films were measured by positioning the postirradiated RCF perpendicular to the CRS monochromatic beam and reading a depth profile of the film along the lateral axis. The Raman peak corresponding to the C ≡ C peak was obtained from a region of interest of 100 × 5 µm² . To investigate the radiosensitization by GNF, two sets of RCF, one attached to a 100-nm thick GNF and the other without GNF were irradiated at 0.5 Gy by 50 and 120 kVp X-rays. The spatial resolution of the CRS on the RCF was quantified by the modulation transfer function method (MTF). Thus, in the spatial resolution determined by MTF, the doses deposited on the films were evaluated. The dose enhancement factor (DEF) was obtained in the measurable micro-size by comparing doses deposited on the RCFs with and without GNF. To verify the experimental results, Monte Carlo simulations following the experimental set up were performed using Geant4. In addition, analytical calculations for the radiosensitization by GNF were carried out.

RESULTS

The confocal Raman spectroscopy on the RCF achieved a spatial resolution of ~6 μm. An experimental DEF within the first 6 μm depth from the surface of RCF was found to be 17.9 for 50 kVp and 14.7 for 120 kVp. The DEF for the same depth obtained by MC and analytical calculations was 13.53 and 9.75 for 50 kVp, and 10.63 and 6.67 for 120 kVp, respectively.

CONCLUSIONS

The experimental DEF as a function of the distance from GNF was consistent with data from previous studies and the MC simulations, supporting that CRS in conjunction with the RCF is a feasible micrometer-resolution dosimeter.

Functional titanium dioxide nanoparticle conjugated with phthalocyanine and folic acid as a promising photosensitizer for targeted photodynamic therapy in vitro and in vivo

Photodynamic therapy (PDT) is a promising cancer treatment that can be implemented using various agents. The conventional photosensitizer Al (III) phthalocyanine chloride tetrasulfonic acid (Pc) has limitations of selectivity in tumor targeting, low affinity to cancer cells, and low two-photon absorption. This study presents a novel photosensitizer FA-TiO₂-Pc, which has the TiO₂ nanoparticle conjugated with a tumor targeting agent of folic acid (FA), and Pc. FA-TiO₂-Pc possessed high targeted photodynamic therapeutic activity and excellent biocompatibility. This promising photosensitizer showed high therapeutic drug efficiency in vitro at a low concentration dose and short incubation time under one-photon excitation (OPE). In vivo, when treated with a low dose of FA-TiO₂-Pc and low light irradiation, the tumor growth was depressed in mice bearing HeLa xenograft tumors with minimal side effects. In addition, the two-photon absorption of FA-TiO₂-Pc was also enhanced compared to Pc, proving that FA-TiO₂-Pc system has a great potential to be used for the therapy of the folate receptor positive cancer cells in both OPE-PDT and two-photon excitation (TPE)-PDT agents.

Obstructions in Nanoparticles Conveyance, Nano-Drug Retention, and EPR Effect in Cancer Therapies

In this chapter, the authors first review nano-devices that are mixtures of biologic molecules and synthetic polymers like nano-shells and nano-particles for the most encouraging applications for different cancer therapies. Nano-sized medications additionally spill especially into tumor tissue through penetrable tumor vessels and are then held in the tumor bed because of diminished lymphatic drainage. This procedure is known as the enhanced penetrability and retention (EPR) impact. Nonetheless, while the EPR impact is generally held to improve conveyance of nano-medications to tumors, it in certainty offers not exactly a 2-overlay increment in nano-drug conveyance contrasted with basic ordinary organs, bringing about medication concentration that is not adequate for restoring most malignant growths. In this chapter, the authors likewise review different obstructions for nano-sized medication conveyance and to make the conveyance of nano-sized medications to tumors progressively successful by expanding on the EPR impact..

Enhanced lysosome escape mediated by 1,2-dicarboxylic-cyclohexene anhydride-modified poly-l-lysine dendrimer as a gene delivery system

Antisense oligodeoxynucleotide (ASODN) can directly interfere a series of biological events of the target RNA derived from tumor cells through Watson-Crick base pairing, in turn, plays antitumor therapeutic roles. In the study, a novel HIF-1α ASODN-loaded nanocomposite was formulated to efficiently deliver gene to the target RNA. The physicochemical properties of nanocomposite were characterized using TEM, FTIR, DLS and zeta potentials. The mean diameter of resulting GEL-DGL-FA-ASODN-DCA nanocomposite was about 170-192 nm, and according to the agarose gel retardation assay, the loading amount of ASODN accounted for 166.7 mg/g. The results of cellular uptake showed that the nanocomposite could specifically target to HepG2 and Hela cells. The cytotoxicity assay demonstrated that the toxicity of vectors was greatly reduced by using DCA to reversibly block the cationic DGL. The subcellular distribution images clearly displayed the lysosomal escape ability of the DCA-modified nanocomposite. In vitro exploration of molecular mechanism indicated that the nanocomposite could inhibit mRNA expression and HIF-1α protein translation at different levels. In vivo optical images and quantitative assay testified that the formulation accumulated preferentially in the tumor tissue. In vivo antitumor efficacy research confirmed that this nanocomposite had significant antitumor activity and the tumor inhibitory rate was 77.99%. These results manifested that the GEL-DGL-FA-ASODN-DCA nanocomposite was promising in gene therapeutics for antitumor by interacting directly with target RNA.

Macrophage-Membrane-Camouflaged Disintegrable and Excretable Nanoconstruct for Deep Tumor Penetration

The consolidation of nanovectors with biological membranes has recently been a subject of interest owing to the prolonged systemic circulation time and delayed clearance by the reticuloendothelial system of such systems. Among the different biomembranes, the macrophage membrane has a similar systemic circulation time, with an additional chemotactic aptitude, targeting integrin proteins. In this study, we aimed to establish a laser-activated, disintegrable, and deeply tumor-penetrative nanoplatform. We used a highly tumor-ablative and laser-responsive disintegrable copper sulfide nanoparticle, loaded it with paclitaxel, and camouflaged it with the macrophage membrane for the fabrication of PTX@CuS@MMNPs. The in vitro paclitaxel release profile was favorable for release in the tumor microenvironment, and the release was accelerated after laser exposure. Cellular internalization was improved by membrane encapsulation. Cellular uptake, cytotoxicity, reactive oxygen species generation, and apoptosis induction of PTX@CuS@MMNPs were further improved upon laser exposure, and boosted permeation was achieved by co-administration of the tumor-penetrating peptide iRGD. In vivo tumor accumulation, tumor inhibition rate, and apoptotic marker expression induced by PTX@CuS@MMNPs were significantly improved by laser irradiation and iRGD co-administration. PTX@CuS@MMNPs induced downregulation of cellular proliferation and angiogenic markers but no significant changes in body weight, survival, or significant toxicities in vital organs after laser exposure, suggesting their biocompatibility. The disintegrability of the nanosystem, accredited to biodegradability, favored efficient elimination from the body. In conclusion, PTX@CuS@MMNPs showed promising traits in combination therapies for excellent tumor eradication.

Dual-targeting tumor cells and tumor associated macrophages with lipid coated calcium zoledronate for enhanced lung cancer chemoimmunotherapy

Lung cancer is the leading cause of cancer death among both men and women, and non-small cell lung cancer (NSCLC) accounts for almost 80% of such death. Tumor associated macrophage (TAMs) are abundant components in NSCLC. TAMs play critical roles in angiogenesis, immune escape and chemoresistance. Here we developed a dual-targeting drug delivery system (CaZOL@BMNPs) of zoledronate, which could bind to both tumor cells with overexpressed biotin receptors and macrophage mannose receptor (MMR) positive TAMs. The biotin- and mannose-modified lipid coated calcium zoledronate nanoparticles were preferentially internalized in both tumor cells and TAMs, and thereby inhibited their survivals. Our studies demonstrated that CaZOl@BMNPs treatment obviously reduced angiogenesis, reprogrammed immunosuppressive tumor microenvironment and eventually restrained tumor progression with negligible systemic toxicity. Collectively, CaZOL@BMNPs could be a promising approach by dual-targeting tumor cells and TAMs for NSCLS chemoimmunotherapy.

Near-Infrared Photoimmunotherapy for Cancers of the Gastrointestinal Tract

BACKGROUND

Cancers of the gastrointestinal (GI) tract are the common leading cause of cancer-related death in the world. Recent advances in cancer therapies such as intensive multidrug chemotherapy and molecular targeted treatment have improved therapeutic efficacy; however, the outcomes are not satisfied. Moreover, these therapies also cause severe side effects. New type of cancer therapies is urgently needed to improve the outcomes and to reduce side effects of GI tract cancers.

SUMMARY

This account is a comprehensive review article on the newly developed, photochemistry-based cancer therapy named as near-infrared photoimmunotherapy (NIR-PIT). NIR-PIT is a highly selective tumor treatment that employs an antibody-photoabsorber conjugate, which is activated by near-infrared light. A world-wide phase 3 clinical trial of NIR-PIT against recurrent head and neck cancer patients is currently underway. NIR-PIT differs from conventional cancer therapies such as surgery, chemotherapy, and radiation in its selectivity for killing cancer cells and cells treated with NIR-PIT leading to immunogenic cell death. Preclinical research in animals with combining cancer-targeting NIR-PIT and other cancer immunotherapies could lead to responses not only in local tumor but also in distant metastases. NIR-PIT also leads to an immediate and dramatic increase in vascular permeability after therapy. From these aspects, NIR-PIT appears to be a promising new form of cancer therapy. NIR-PIT could be readily translated into clinical use for virtually any cancers in the near future provided suitable humanized antibodies are available. Here, we describe the specific advantages and applications of NIR-PIT in the GI tract. Key Messages: We believe that NIR-PIT with NIR excitation light, which can be delivered via a fiber optic diffuser through endoscopes, is a promising method for a new treatment of GI cancers.

Stimuli-Responsive Aliphatic Polycarbonate Nanocarriers for Tumor-Targeted Drug Delivery

Nanoparticles based on amphiphilic copolymers with tunable physicochemical properties can be used to encapsulate delicate pharmaceutics while at the same time improving their solubility, stability, pharmacokinetic properties, reducing immune surveillance, or achieving tumor-targeting ability. Those nanocarriers based on biodegradable aliphatic polycarbonates are a particularly promising platform for drug delivery due to flexibility in the design and synthesis of appropriate monomers and copolymers. Current studies in this field focus on the design and the synthesis of new effective carriers of hydrophobic drugs and their release in a controlled manner by exogenous or endogenous factors in tumor-specific regions. Reactive groups present in aliphatic carbonate copolymers, undergo a reaction under the action of a stimulus: e.g., acidic hydrolysis, oxidation, reduction, etc. leading to changes in the morphology of nanoparticles. This allows the release of the drug in a highly controlled manner and induces a desired therapeutic outcome without damaging healthy tissues. The presented review summarizes the current advances in chemistry and methods for designing stimuli-responsive nanocarriers based on aliphatic polycarbonates for controlled drug delivery.

DNA Nanostructures and DNA-Functionalized Nanoparticles for Cancer Theranostics

In the last two decades, DNA has attracted significant attention toward the development of materials at the nanoscale for emerging applications due to the unparalleled versatility and programmability of DNA building blocks. DNA-based artificial nanomaterials can be broadly classified into two categories: DNA nanostructures (DNA-NSs) and DNA-functionalized nanoparticles (DNA-NPs). More importantly, their use in nanotheranostics, a field that combines diagnostics with therapy via drug or gene delivery in an all-in-one platform, has been applied extensively in recent years to provide personalized cancer treatments. Conveniently, the ease of attachment of both imaging and therapeutic moieties to DNA-NSs or DNA-NPs enables high biostability, biocompatibility, and drug loading capabilities, and as a consequence, has markedly catalyzed the rapid growth of this field. This review aims to provide an overview of the recent progress of DNA-NSs and DNA-NPs as theranostic agents, the use of DNA-NSs and DNA-NPs as gene and drug delivery platforms, and a perspective on their clinical translation in the realm of oncology.

Zein nanoparticles as nontoxic delivery system for maytansine in the treatment of non-small cell lung cancer

Purpose: Maytansine (DM1) is a potent anticancer drug and limited in clinical application due to its poor water solubility and toxic side effects. Zein is widely used in nano drug delivery systems due to its good biocompatibility. In this study, we prepared DM1-loaded zein nanoparticles (ZNPs) to achieve tumor targeting and reduce toxic side effects of DM1. Methods: ZNPs were prepared by phase separation and Box-Behnken design was used to optimize the formulation. Then, confocal fluorescence microscope and flow cytometry were used to determine cellular uptake of ZNPs. A549 cells were cultured in vitro to study cytotoxicity and used to establish tumor xenografts in nude mice. Biodistribution and antitumor activity of ZNPs were performed in vivo experiments. In addition, we also performed histological and immunohistochemical examinations on tumors and viscera. Results: The optimal prescription was obtained by using 120 μL zein added to 2 mL water under stirring in 300 rpm. The encapsulation efficiency and drug loading were 82.97 ± 0.80% and 3.32 ± 0.03%, respectively. We found that DM1-loaded ZNPs have a strong inhibitory effect on A549 cells, which stemmed from the ability of ZNPs to enhance cellular uptake. Furthermore, we demonstrated that DM1-loaded ZNPs exhibits a better antitumor efficacy than DM1, which tumor inhibition rate were 97.3% and 92.7%, respectively. The biodistribution revealed that ZNPs could targeted to tumor. Finally, we confirmed by histological that DM1-loaded ZNPs are nontoxic. Conclusion: DM1-loaded ZNPs have considerable antitumor activity. Thus, DM1-loaded ZNPs are a promising treatment of non-small cell lung cancer.

Paying attention to tumor blood vessels: Cancer phototherapy assisted with nano delivery strategies

Cancer phototherapy has attracted increasing attention for its promising effectiveness and relative non-invasiveness. Over the past years, tremendous efforts have been made to develop better phototherapy strategies with various nano delivery systems. This review introduces cancer phototherapy strategies based on tumor blood vessels for improved therapeutic outcomes from the angle of direct tumor destruction and improved delivery process assisted with nano delivery designs. Latest directions and ideas of cancer phototherapy with translation potential are also discussed. Focusing on the double role of tumor vessels not only as an anti-tumor target but also as part of the delivery process, we highlight the crosstalk between photo-induced extensive effects and the complicated drug delivery process. Due to the heterogeneity of tumors, deeper investigations about the interconnection between tumor vessels and cancer phototherapy remain to be carried out. More delicate and intelligent nano delivery systems are expected to help realize the full potential of this therapeutic strategy.

A versatile and multifunctional metal-organic framework nanocomposite toward chemo-photodynamic therapy

Previously most of the applications of targeting components have been based on the enhanced permeability and retention effect achieved using folic acid, which consider the side effects of the targeting components to some extent. Herein, we report a new strategy to decorate the surface of MOFs using a pemetrexed (MTA) targeting molecule, affording a new drug delivery system of ALA@UIO-66-NH-FAM/MTA (ALA = 5-amino-levulinic acid and FAM = 5-carboxyfluorescein). The confocal microscopy and flow cytometry results showed that ALA@UIO-66-NH-FAM/MTA presented a better targeting effect compared to ALA@UIO-66-NH-FAM/FA (FA = folic acid) and indicated a gradually increasing tendency of the targeting effect with the increasing expression of folate receptors on the tumor cell cytomembrane. Furthermore, the cytotoxicity experiment indicates that the combination of chemotherapy and photodynamic therapy is a more effective therapy model than single chemotherapy and photodynamic therapy. This work demonstrates the first attempt at folic acid antagonist (MTA) modification for NMOFs, providing a new concept for the design of MOFs with folate receptor targeting capacity for clinical applications.

Nanotheranostics for Cancer Therapy and Detection: State of the Art

Nanotheranostics, an approach of combining both diagnosis and therapy, is one of the latest advances in cancer therapy particularly. Nanocarriers designed and derived from inorganic materials such as like gold nanoparticles, silica nanoparticles, magnetic nanoparticles and carbon nanotubes have been explored for tremendous applications in this area. Similarly, nanoparticles composed of some organic material alone or in combination with inorganic nano-cargos have been developed pre-clinically and possess excellent features desired. Photothermal therapy, MRI, simultaneous imaging and delivery, and combination chemotherapy with a diagnosis are a few of the known methods exploring cancer therapy and detection at organ/tissue/molecular/sub-cellular level. This review comprises an overview of the recent reports meant for nano theranostics purposes. Targeted cancer nanotheranostics have been included for understating tumor micro-environment or cell-specific targeting approach employed. A brief account of various strategies is also included for the readers highlighting the mechanism of cancer therapy.

Pluronic-based nanovehicles: Recent advances in anticancer therapeutic applications

Pluronics are a class of amphiphilic tri-block copolymers with wide pharmaceutical applicability. In the past decades, the ability to form biocompatible nanosized micelles was exploited to formulate stable drug nanovehicles with potential use in antitumor therapy. Due to the great potential for tuning physical and structural properties of Pluronic unimers, a panoply of drug or polynucleotide-loaded micelles was prepared and tested for their antitumoral activity. The attractive inherent antitumor properties of Pluronic polymers in combination with cell targeting and stimuli-responsive ligands greatly improved antitumoral therapeutic effects of tested drugs. In spite of that, the extraordinary complexity of biological challenges in the delivery of micellar drug payload makes their therapeutic potential still not exploited to the fullest. In this review paper we attempt to present the latest developments in the field of Pluronic based nanovehicles and their application in anticancer therapy with an overview of the chemistry involved in the preparation of these nanovehicles.

Design, characterization, and intracellular trafficking of biofunctionalized chitosan nanomicelles

The hydrophobically modified glycol chitosan (HGC) nanomicelle has received increasing attention as a promising platform for the delivery of chemotherapeutic drugs. To improve the tumor selectivity of HGC, here an avidin and biotin functionalization strategy was applied. The hydrodynamic diameter of the biotin-avidin-functionalized HGC (cy5.5-HGC-B4F) was observed to be 104.7 nm, and the surface charge was +3.1 mV. Confocal and structured illumination microscopy showed that at 0.1 mg/ml, cy5.5-HGC-B4F nanomicelles were distributed throughout the cytoplasm of MDA-MB-231 breast cancer cells after 2 h of exposure without significant cytotoxicity. To better understand the intracellular fate of the nanomicelles, entrapment studies were performed and demonstrated that some cy5.5-HGC-B4F nanomicelles were capable of escaping endocytic vesicles, likely via the proton sponge effect. Quantitative analysis of the movements of endosomes in living cells revealed that the addition of HGC greatly enhanced the motility of endosomal compartments, and the nanomicelles were transported by early and late endosomes from cell periphery to the perinuclear region. Our results validate the importance of using live-cell imaging to quantitatively assess the dynamics and mechanisms underlying the complex endocytic pathways of nanosized drug carriers.

Hairpin Oligonucleotide Can Functionalize Gold Nanorods for in Vivo Application Delivering Cytotoxic Nucleotides and Curcumin: A Comprehensive Study in Combination with Near-Infrared Laser

We prepared a multimodality nanocomplex by functionalizing gold nanorods (GNRs) with a cytotoxic nucleoside, 5-fluoro-2'-deoxyuridine (FdU) containing a DNA hairpin, along with complexation of pleiotropic molecule curcumin. Conjugates were investigated for anti-tumor activity using an Ehrlich carcinoma model in combination with 808 nm laser irradiation. We demonstrated that hairpin-functionalized GNRs are suitable for intravenous administration, including delivery of cytotoxic nucleotides and curcumin. Curcumin binding with FdU-hairpin-functionalized GNRs displayed improved anti-tumor activity in part by inducing a lymphocyte-mediated immune response. The complex showed notable photothermal activity in vitro; however, 808 nm laser irradiation of the tumor following treatment with the complex did not increase the anti-tumor effect significantly. Biodistribution studies depicted that the nanoconjugates localized primarily in the sinusoidal structures of the liver and spleen with minimal tumor accumulation. Curcumin complexation alleviated the reduction in the RBC count that was observed for the conjugate without curcumin, especially in combination with laser irradiation. Localization of FdU-hairpin-GNR conjugates in the liver and spleen evoked an inflammatory response, which was mitigated by curcumin complexation. However, no functional abnormality was found in the liver in any case. Curcumin binding also notably decreased nanoconjugate accumulation in lungs and significantly reduced inflammation. Biodistribution studies were consistent with previous reports, suggesting that optimization of the GNR size and surface coating is required for more efficient tumor localization via the enhanced permeability and retention (EPR) effect. Our studies demonstrate that DNA/RNA hairpins are suitable for GNR surface functionalization and enable delivery of cytotoxic nucleotides as well as curcumin in vivo with potential for synergistic anti-cancer therapy.