A designer bow-tie combination therapeutic platform: An approach to resistant cancer treatment by simultaneous delivery of cytotoxic and anti-inflammatory agents and radiation

Cell specific mitochondria targeted metabolic alteration for precision medicine

Mitochondria play important roles in the maintenance of cellular health. In cancer, these dynamic organelles undergo significant changes in terms of membrane hyperpolarization, altered metabolic functions, fusion-fission balance, and several other parameters. These alterations promote cancer growth, proliferation and spread, and the eventual development of metastatic disease and therapeutic resistance. Thus, routing therapeutics to the mitochondrial compartments can be one of the most promising methodologies for tackling such changes to achieve cancer control. Over the last decade, targeted cancer medicine has experienced tremendous growth, enabling the targeting of mitochondria for greater therapeutic specificity. Here, we demonstrate a feasibility method to specifically target the mitochondria of prostate cancer cells. We achieve such dual targeting by utilizing two functionalized polymers and constructing a single blended nanoparticle (NP). Such a targeting strategy was developed utilizing a polymeric platform that differed in terms of the length of the amphiphilic portions, the linker between the hydrophobic portions, and the attached targeting moieties. In doing this, we demonstrate prostate cancer specific mitochondrial delivery of a chemotherapeutic prodrug to create repair-resistant adducts within mitochondrial DNA promoting cellular death. This article documents the synthetic strategy, optimization of blended NPs for cell specific mitochondria targeting, and the utility of the proof-of-concept design was demonstrated using a combination of analytical and in vitro studies.

Lipid Metabolism Modulatory Cisplatin Prodrug Sensitizes Resistant Prostate Cancer toward Androgen Deprivation Therapy

Mainstream treatment modalities which dominate the therapeutic landscape of prostate cancer (PCa) are prostatectomy, radiation therapy, and androgen deprivation therapy (ADT) or castration. These therapeutic options can extend the life expectancy of the patients but eventually fail to completely cure the disease. Despite undergoing ADT, patients still experience disease recurrence. One of the reasons for this recurrence is the binding of the basal androgens present in blood plasma to the androgen receptor (AR). At this stage, the disease becomes castration-resistant prostate cancer (CRPC) showing resistance to ADT promoting progression, and there is no effective treatment available. Although another male cancer such as testicular cancer responds to cisplatin-based therapy very well, PCa is resistant to cisplatin. In our continued effort to find the pathways that are important for such resistance, we link in this report, tumor metabolism driven androgen regulation and PCa resistance toward cisplatin-based therapy. To delve deeper into understanding how metabolic modulatory cisplatin prodrugs can be used to target the ADT resistant population, we demonstrate that metabolic inhibition by a cisplatin prodrug, Platin-L has the potential to modulate AR activity and resensitize ADT resistant cells toward cisplatin-based chemotherapy as well as ADT. The mode of action for Platin-L is inhibition of fatty acid oxidation (FAO) of prostate cancer cells. We demonstrated that FAO inhibition by Platin-L in PCa cells contribute to AR regulation resulting in altered tumorigenicity of androgen sensitive prostate cancer.

Stemness, invasion, and immunosuppression modulation in recurrent glioblastoma using nanotherapy

The recurrent nature of glioblastoma negatively impacts conventional treatment strategies leading to a growing need for nanomedicine. Nanotherapeutics, an approach designed to deliver drugs to specific sites, is experiencing rapid growth and gaining immense popularity. Having potential in reaching the hard-to-reach disease sites, this field has the potential to show high efficacy in combatting glioblastoma progression. The presence of glioblastoma stem cells (GSCs) is a major factor behind the poor prognosis of glioblastoma multiforme (GBM). Stemness potential, heterogeneity, and self-renewal capacity, are some of the properties that make GSCs invade across the distant regions of the brain. Despite advances in medical technology and MRI-guided maximal surgical resection, not all GSCs residing in the brain can be removed, leading to recurrent disease. The aggressiveness of GBM is often correlated with immune suppression, where the T-cells are unable to infiltrate the cancer initiating GSCs. Standard of care therapies, including surgery and chemotherapy in combination with radiation therapy, have failed to tackle all the challenges of the GSCs, making it increasingly important for researchers to develop strategies to tackle their growth and proliferation and reduce the recurrence of GBM. Here, we will focus on the advancements in the field of nanomedicine that has the potential to show positive impact in managing glioblastoma tumor microenvironment. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Preparation, Biological Evaluation, and First-in-Human Single-Photon Emission Computed Tomography (SPECT) Study of 99mTc-Labeled Prostate-Specific Membrane Antigen (PSMA)-Targeted Radiotracers Containing Triazole with Reduced Kidneys Accumulation

Prostate-specific membrane antigen (PSMA), a well-established biological marker for prostate cancer (PCa) imaging and therapy, is overexpressed on the surface of prostate cancer lesions. In this study, a triazole ring was introduced into the linker by click chemistry to generate a HYNIC-derived ligand (T), which exhibited good PSMA affinity (Ki = 2.23 nM). Eight stable 99mTc-labeled complexes, [99mTc]Tc-T-Mn (n = 1-8), with hydrophilic properties were synthesized by incorporating different coligands at high radiochemical yields and purities without purification. The radioligands were concentrated in the kidneys of healthy Kunming male mice and were significantly blocked by the PSMA inhibitor ZJ-43. The uptake of the optimized complex [99mTc]Tc-T-M2 was correlated with PSMA, and it had good PSMA affinity (Kd = 5.42 nM). [99mTc]Tc-T-M2 accumulated on LNCaP (PSMA++) tumors and was significantly blocked by ZJ-43 at 2 h p.i., indicating high PSMA specificity. Relatively suitable kidney uptake was beneficial for reducing kidneys exposure in patients. SPECT/CT imaging of [99mTc]Tc-T-M2 in LNCaP (PSMA++) or 22Rv1 (PSMA+) tumor-bearing mice revealed high tumor uptake, low background uptake (especially low kidney uptake (49.06 ± 9.20 %ID/g) at 2 h p.i.), and obvious inhibition by ZJ-43, whereas PC-3 (PSMA-) tumors were undetectable. A freeze-dried [99mTc]Tc-T-M2 kit was successfully developed (T-M2 kit). Preliminary clinical trials showed that [99mTc]Tc-T-M2 clearly identified small prostate cancer lesions and has potential for clinical application.

Engineered nanomicelles inhibit the tumour progression via abrogating the prostaglandin-mediated immunosuppression

Cancer treatment is challenged due to immunosuppressive inflammatory tumour microenvironment (TME) caused by infiltration of tumour-promoting and inhibition of tumour-inhibiting immune cells. Here, we report the engineering of chimeric nanomicelles (NMs) targeting the cell proliferation using docetaxel (DTX) and inflammation using dexamethasone (DEX) that alters the immunosuppressive TME. We show that a combination of phospholipid-DTX conjugate and PEGylated-lipid-DEX conjugate can self-assemble to form sub-100 nm chimeric NMs (DTX-DEX NMs). Anti-cancer activities against syngeneic and xenograft mouse models showed that the DTX-DEX NMs are more effective in tumour regression, enhance the survival of mice over other treatment modes, and alter the tumour stroma. DTX-DEX NMs cause a significant reduction in myeloid-derived suppressor cells, alter the polarization of macrophages, and enhance the accumulation of cytotoxic CD4+ and CD8+ T cells in tumour tissues, along with alterations in cytokine expression. We further demonstrated that these DTX-DEX NMs inhibit the synthesis of prostaglandins, especially PGE2, by targeting the cyclooxygenase 2 that is partly responsible for immunosuppressive TME. Therefore, this study presents, for the first time, the engineering of lithocholic acid-derived chimeric NMs that affect the prostaglandin pathway, alter the TME, and mitigate tumour progression with enhanced mice survival.

Drug Delivery to the Brain: Recent Advances and Unmet Challenges

Brain cancers and neurodegenerative diseases are on the rise, treatments for central nervous system (CNS) diseases remain limited. Despite the significant advancement in drug development technology with emerging biopharmaceuticals like gene therapy or recombinant protein, the clinical translational rate of such biopharmaceuticals to treat CNS disease is extremely poor. The blood-brain barrier (BBB), which separates the brain from blood and protects the CNS microenvironment to maintain essential neuronal functions, poses the greatest challenge for CNS drug delivery. Many strategies have been developed over the years which include local disruption of BBB via physical and chemical methods, and drug transport across BBB via transcytosis by targeting some endogenous proteins expressed on brain-capillary. Drug delivery to brain is an ever-evolving topic, although there were multiple review articles in literature, an update is warranted due to continued growth and new innovations of research on this topic. Thus, this review is an attempt to highlight the recent strategies employed to overcome challenges of CNS drug delivery while emphasizing the necessity of investing more efforts in CNS drug delivery technologies parallel to drug development.

New Pathway for Cisplatin Prodrug to Utilize Metabolic Substrate Preference to Overcome Cancer Intrinsic Resistance

Tumor cells adapt to diverse survival strategies defying our pursuit of multimodal cancer therapy. Prostate cancer (PCa) is an example that is resistant to one of the most potent chemotherapeutics, cisplatin. PCa cells survive and proliferate using fatty acid oxidation (FAO), and the dependence on fat utilization increases as the disease progresses toward a resistant form. Using a pool of patient biopsies, we validated the expression of a key enzyme carnitine palmitoyltransferase 1 A (CPT1A) needed for fat metabolism. We then discovered that a cisplatin prodrug, Platin-L, can inhibit the FAO of PCa cells by interacting with CPT1A. Synthesizing additional cisplatin-based prodrugs, we documented that the presence of an available carboxylic acid group near the long chain fatty acid linker on the Pt(IV) center is crucial for CPT1A binding. As a result of fat metabolism disruption by Platin-L, PCa cells transition to an adaptive glucose-dependent chemosensitive state. Potential clinical translation of Platin-L will require a delivery vehicle to direct it to the prostate tumor microenvironment. Thus, we incorporated Platin-L in a biodegradable prostate tumor-targeted orally administrable nanoformulation and demonstrated its safety and efficacy. The distinctive FAO inhibitory property of Platin-L can be of potential clinical relevance as it offers the use of cisplatin for otherwise resistant cancer.

Platin-C containing nanoparticles: a recipe for the delivery of curcumin-cisplatin combination chemotherapeutics to mitochondria

The success story of cisplatin spans over six decades now and yet it continues to be the key player in most chemotherapeutic regimens. Numerous efforts have been made to improve its efficacy, address its shortcomings, and overcome drug resistance. One such strategy is to develop new platinum(IV)-based prodrugs with functionally active ligands to deliver combination therapeutics. This strategy not only enables the drug candidate to access multiple drug targets but also enhances the kinetic inertness of platinum complexes and thereby ensures greater accumulation of active drugs at the target site. We report the synthesis of Platin-C, a platinum(IV)-based cisplatin prodrug tethered to the active component of ancient herbal medicine, curcumin, as one of the axial ligands. This combination complex showed improved chemotherapeutic efficacy in cisplatin resistant A2780/CP70 cell lines compared with the individual components. An amine-terminated biodegradable polymer was suitably functionalized with the triphenylphosphonium (TPP) cation to obtain a mitochondria-directed drug delivery platform. Quantification of Platin-C loading into these NPs using complementary techniques employing curcumin optical properties in high-performance liquid chromatography and platinum-based inductively coupled plasma mass spectrometry evidenced efficacious payload incorporation resulting in functional activities of both the components. Stability studies for a period of one week indicated that the NPs remain stable, enabling substantial loading and controlled release of the prodrug. The targeting nanoparticle (NP) platform was utilized to deliver Platin-C primarily in the mitochondrial network of cancer cells as monitored using confocal microscopy employing the green fluorescence of the curcumin pendant. Our studies showed that amine terminated NPs were relatively less efficient in their ability to target mitochondria despite being positively charged. This re-validated the importance of lipophilic positively charged TPP surface functionalities to successfully target cellular mitochondria. We validated the capabilities of Platin-C and its mitochondria-targeting nanoparticles towards inflicting mitochondria-directed activity in cisplatin-sensitive and cisplatin-resistant cell lines. Furthermore, our studies also demonstrated the effectiveness of Platin-C incorporated targeting NPs in attenuating cellular inflammatory markers by utilizing the curcumin component. This study advances our understanding of the cisplatin prodrug approach to combine chemotherapeutic and inflammatory effects in accessing combinatory pathways.

A Theranostic Nanocomplex Combining with Magnetic Hyperthermia for Enhanced Accumulation and Efficacy of pH-Triggering Polymeric Cisplatin(IV) Prodrugs

Although polymeric platinum(IV) (Pt(IV)) prodrugs can reduce the side effects of cisplatin, the efficacy of the prodrug is still limited by its non-targeted distribution, poor penetration in deep tumor tissue, and low cytotoxicity in tumor cells. To improve the clinical potential of polymeric prodrug micelle, we synthesized amphiphilic polymeric Pt(IV) with high Pt content (22.5%), then developed a theranostic nanocomplex by integrating polymeric Pt(IV) with superparamagnetic Mn_0.6Zn_0.4Fe₂O₄ via simple self-assembly. Due to the high content of Mn_0.6Zn_0.4Fe₂O₄ (41.7% w/w), the theranostic nanocomplex showed high saturation magnetization (103.1 emu g⁻¹) and excellent magnetocaloric effect (404 W g⁻¹), both of them indicating its advantages in efficient magnetic targeting (MT), magnetic hyperthermia (MH), and magnetic resonance imaging (MRI). In vitro, in combination with MH, the theranostic nanocomplex showed as high cytotoxicity as cisplatin because of a significant increase in platinum of cellular uptake. In vivo, the accumulation of theranostic nanocomplex in tumors was increased by MT and confirmed by MRI. Furthermore, MH improved penetration of theranostic nanocomplex in tumors as expanding blackened area in tumors was observed by MRI. Based on these properties, the theranostic nanocomplex, under the assistance of MT and MH, showed the highest tumor growth inhibition rate (88.38%) after different treatments, while the body weight of mice increased slightly, indicating low side effects compared to those of cisplatin. The study provided an advanced theranostic nanocomplex with low toxicity and high efficacy, indicating a great clinical potential of polymeric Pt(IV).

Intersection of Inorganic Chemistry and Nanotechnology for the Creation of New Cancer Therapies

Since its discovery in 1965, the inorganic drug cisplatin has become a mainstay of cancer therapies and has inspired many platinum (Pt)-based compounds to solve various issues of toxicity and limitations associated with the original cisplatin. However, many of these drugs/prodrugs continue to be plagued by an array of side effects, limited circulation, and half-life and off-target effects. To solve this issue, we have constructed an array of platinum-based prodrugs on a Pt(IV) skeleton, which provides more favorable geometry and hydrophobicity, easier functionalization, and ultimately better targeting abilities. Each of these Pt(IV) prodrugs aims to either combine cisplatin with other agents for a combination therapeutic effect or improve the targeting of cisplatin itself, all for the more effective treatment of specific cancers. Our developed prodrugs include Platin-A, which combines cisplatin with the anti-inflammatory agent aspirin, Platin-M, which is functionalized with a mitochondria-targeting moiety, and Platin-B and Platin-Cbl, which combine cisplatin with components to combat cellular resistance to chemotherapy. At the same time, however, we recognize the crucial role of nanotechnology in improving the efficacy of cisplatin prodrugs and other inorganic compounds for the treatment of cancers. We describe several key benefits provided by nanomedicine that vastly improve the reach and utility of cisplatin prodrugs, including the ability of biodegradable polymeric nanoparticles (NPs) to deliver these agents with precision to the mitochondria, transport drugs across the blood-brain barrier, and target cisplatin prodrugs to specific cancers using various ligands. In addition, we highlight our progress in the engineering of innovative new polymers to improve the release patterns, pharmacokinetics, and dosages of cancer therapies. In this Account, we aim to describe the growing need for collaboration between the fields of inorganic chemistry and nanotechnology and how new advancements can not only improve on traditional chemotherapeutic agents but also expand their reach to entirely new subsets of cancers. In addition to detailing the design and principles behind our modifications of cisplatin and the efficacy of these new prodrugs against aggressive, cisplatin-resistant, or metastatic cancers, we also shed light on nanotechnology's essential role in protecting inorganic drugs and the human body from one another for more effective disease treatment without the off-target effects with which it is normally associated. We hope that this perspective into the important intersection between inorganic medicinal chemistry and nanotechnology will inspire future research on cisplatin prodrugs and other inorganic agents, innovative polymer and NP design, and the ways in which these two fields can greatly advance cancer treatment.

Controlled release nanoplatforms for three commonly used chemotherapeutics

In order to combat an evolving, multidimensional disease such as cancer, research has been aimed at synthesizing more efficient and effective versions of popular chemotherapeutic drugs. Despite these efforts, there remains a necessity for the development of suitable delivery vehicles that can both harness the chemotherapeutic effects meanwhile reducing some of the known issues when using these drugs such as unwanted side-effects, acquired drug resistance, and associated difficulties with drug delivery. Synthetic drug discovery approaches focusing on modification of the native structure of these chemotherapeutic drugs often face challenges such as loss of efficacy, as well as a potential worsening of side-effects. Synthetic chemists are then left with increasingly narrow choices for possible chemistry they could implement to achieve the desired therapy. The emergence of targeted therapies using controlled-release nanomaterials can provide many opportunities for conventional chemotherapeutic drugs to be delivered to specific target sites, ultimately leading to reduced side-effects and improved efficacy. Logically, it may prove advantageous to consider nano-delivery systems as a likely candidate for circumventing some of the barriers associated with creating viable drug therapies. In this review, we summarize controlled release nanoformulations of the three most widely used and approved chemotherapeutics, doxorubicin, paclitaxel, and cisplatin as an alternative therapeutic approach against different cancer types.

Blending of Designer Synthetic Polymers to a Dual Targeted Nanoformulation for SARS-CoV-2 Associated Kidney Damage

As the COVID-19 pandemic has continued to spread, studies have shown that hospitalized COVID-19 patients are at significant risk for developing acute kidney injury (AKI), which can cause increased morbidity, the need for dialysis treatment, chronic kidney diseases, and even death. In this paper, we present a proof-of-concept study for the utilization of combination therapeutic-loaded dual-targeted biodegradable nanoparticles (NPs) to treat concurrent AKI and COVID-19 in patients by delivering the therapeutics across the gut epithelial barrier and to the kidney, in order to lower the viral load as well as reduce the symptoms of AKI. Despite recent vaccination efforts and the end of the COVID-19 pandemic in sight, problems related to the long-term effects of COVID-19 will continue to persist, including impacts on patients suffering from AKI and other chronic renal conditions. Therefore, the dual-targeted blended polymeric NP developed in this study to treat concurrent COVID-19 infection and AKI is a useful proof-of-concept nanoplatform for future treatments of these complications.

Nanoparticulation of Prodrug into Medicines for Cancer Therapy

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Nanotherapeutic approach to tackle chemotherapeutic resistance of cancer stem cells

Estimates indicate that cancer will become the leading cause of mortality worldwide in the future. Tumorigenesis is a complex process that involves self-sufficiency in signs of growth, insensitivity to anti-growth signals, prevention of apoptosis, unlimited replication, sustained angiogenesis, tissue invasion, and metastasis. Cancer stem cells (CSCs) have an important role in tumor development and resistance. Here we will approach phenotypic plasticity capacity, highly efficient DNA repair systems, anti-apoptotic machinery, sustained stemness features, interaction with the tumor microenvironment, and Notch, Wnt, and Hedgehog signaling pathways. The researches about CSCs as a target in cancer treatment has been growing. Many different options have pointed beneficial results, such as pathways and CSC-surface markers targeting. Besides its limitations, nanotherapeutics have emerged as a potential strategy in this context since they aim to improve pharmacokinetics, biodistribution, and reduce the side effects observed in traditional treatments. Nanoparticles have been studied in this field, mostly for drug delivery and a multitherapy approach. Another widely researched approaches in this area are related to heat therapy, such as photothermal therapy, photodynamic therapy and magnetic hyperthermia, besides molecular targeting. This review will contemplate the most relevant studies that have shown the effects of nanotherapeutics. In conclusion, although the studies analyzed are mostly preclinical, we believe that there is strong evidence that nanoparticles can increase the chances of a better prognosis to cancer in the future. It is also essential to transpose these findings to the clinic to confirm and better understand the role of nanotherapeutics in this context.

Protease-triggered bioresponsive drug delivery for the targeted theranostics of malignancy

Proteases have a fundamental role in maintaining physiological homeostasis, but their dysregulation results in severe activity imbalance and pathological conditions, including cancer onset, progression, invasion, and metastasis. This striking importance plus superior biological recognition and catalytic performance of proteases, combining with the excellent physicochemical characteristics of nanomaterials, results in enzyme-activated nano-drug delivery systems (nanoDDS) that perform theranostic functions in highly specific response to the tumor phenotype stimulus. In the tutorial review, the key advances of protease-responsive nanoDDS in the specific diagnosis and targeted treatment for malignancies are emphatically classified according to the effector biomolecule types, on the premise of summarizing the structure and function of each protease. Subsequently, the incomplete matching and recognition between enzyme and substrate, structural design complexity, volume production, and toxicological issues related to the nanocomposites are highlighted to clarify the direction of efforts in nanotheranostics. This will facilitate the promotion of nanotechnology in the management of malignant tumors.

Nanomaterials to Fight Cancer: An Overview on Their Multifunctional Exploitability

In recent years the worldwide research community has highlighted innumerable benefits of nanomaterials in cancer detection and therapy. Nevertheless, the development of cancer nanomedicines and other bionanotechnology requires a huge amount of considerations about the interactions of nanomaterials and biological systems, since long-term effects are not yet fully known. Open issues remain the determination of the nanoparticles distributions patterns and the internalization rate into the tumor while avoiding their accumulation in internal organs or other healthy tissues. The purpose of this work is to provide a standard overview of the most recent advances in nanomaterials to fight cancer and to collect trends and future directions to follow according to some critical aspects still present in this field. Complementary to the very recent review of Wolfram and Ferrari which discusses and classifies successful clinically-approved cancer nanodrugs as well as promising candidates in the pipeline, this work embraces part of their proposed classification system based on the exploitation of multifunctionality and extends the review to peer-reviewed journal articles published in the last 3 years identified through international databases.

Microphysiological systems in early stage drug development: Perspectives on current applications and future impact

Microphysiological systems (MPS) are making advances to provide more standardized and predictive physiologically relevant responses to test articles in living tissues and organ systems. The excitement surrounding the potential of MPS to better predict human responses to medicines and improving clinical translation is overshadowed by their relatively slow adoption by the pharmaceutical industry and regulators. Collaboration between multiorganizational consortia and regulators is necessary to build an understanding of the strengths and limitations of MPS models and closing the current gaps. Here, we review some of the advances in MPS research, focusing on liver, intestine, vascular system, kidney and lung and present examples highlighting the context of use for these systems. For MPS to gain a foothold in drug development, they must have added value over existing approaches. Ideally, the application of MPS will augment in vivo studies and reduce the use of animals via tiered screening with less reliance on exploratory toxicology studies to screen compounds. Because MPS support multiple cell types (e.g. primary or stem-cell derived cells) and organ systems, identifying when MPS are more appropriate than simple 2D in vitro models for understanding physiological responses to test articles is necessary. Once identified, MPS models require qualification for that specific context of use and must be reproducible to allow future validation. Ultimately, the challenges of balancing complexity with reproducibility will inform the promise of advancing the MPS field and are critical for realization of the goal to reduce, refine and replace (3Rs) the use of animals in nonclinical research.

Preparation and Biological Evaluation of [99mTc]Tc-CNGU as a PSMA-Targeted Radiotracer for the Imaging of Prostate Cancer

Prostate-specific membrane antigen (PSMA) is a well-established biological target that is overexpressed on the surface of prostate cancer lesions. Radionuclide-labeled small-molecule PSMA inhibitors have been shown to be promising PSMA-specific agents for the diagnosis and therapy of prostate cancer. In this study, a glutamate-urea-based PSMA-targeted ligand containing an isonitrile (CNGU) was synthesized and labeled with ^99mTc to prepare [^99mTc]Tc-CNGU with a high radiochemical purity (RCP). The CNGU ligand showed a high affinity toward PSMA (K_i value is 8.79 nM) in LNCaP cells. The [^99mTc]Tc-CNGU exhibited a good stability in vitro and hydrophilicity (log P = −1.97 ± 0.03). In biodistribution studies, BALB/c nude mice bearing LNCaP xenografts showed that the complex had a high tumor uptake with 4.86 ± 1.19% ID/g, which decreased to 1.74 ± 0.90% ID/g after a pre-injection of the selective PSMA inhibitor ZJ-43, suggesting that it was a PSMA-specific agent. Micro-SPECT imaging demonstrated that the [^99mTc]Tc-CNGU had a tumor uptake and that the uptake was reduced in the image after blocking with ZJ-43, further confirming its PSMA specificity. All of the results in this work indicated that [^99mTc]Tc-CNGU is a promising PSMA-specific tracer for the imaging of prostate cancer.

Reduction-sensitive platinum (IV)-prodrug nano-sensitizer with an ultra-high drug loading for efficient chemo-radiotherapy of Pt-resistant cervical cancer in vivo

Cisplatin is widely used in the chemoradiotherapy (CRT) of cervical cancers. However, despite the severe systemic side effects, the therapeutic efficacy of cisplatin is often compromised by the development of drug resistance, which is closely related to the elevated intracellular thiol-containing species (especially glutathione (GSH)) and the adenosine triphosphate (ATP)-dependent glutathione S-conjugate pumps. The construction of a safe and redox-sensitive nano-sensitizer with high disulfide density and high Pt(IV) prodrug loading capacity (up to 16.50% Pt and even higher), as described herein, is a promising way to overcome the cisplatin resistance and enhance the CRT efficacy. The optimized nanoparticles (NPs) (referred to as ^SSCV₅) with moderate Pt loading (7.62% Pt) and median size (c.a. 40 nm) was screened out and used for further biological evaluation. Compared with free cisplatin, more drugs could be transported and released inside the cisplatin resistant cells (Hela-CDDP) by ^SSCV₅ NPs. With the synergistic effect of GSH scavenging and mitochondrial damage, ^SSCV₅ NPs can easily reverse the cisplatin resistance. Moreover, the higher nucleus DNA binding Pt content of ^SSCV₅ NPs not only caused the DNA damage and apoptosis of Hela-CDDP cells but also sensitized these cells to X-Ray radiation. The in vivo safety and efficacy results showed that ^SSCV₅ NPs effectively accumulated inside tumor and inhibited the growth of cisplatin resistant xenograft models while alleviating the serious side effect associated with cisplatin (the maximum tolerated cisplatin equivalent of single injection is higher than 20 mg/kg body weight). The intervention of exogenous radiation further improved the anticancer efficacy of ^SSCV₅ NPs and caused the shrinkage of tumor volume, thus making this safe and facile nano-sensitizer a promising route for the neoadjuvant CRT of cervical cancers.