Perfluorocarbon nanodroplets stabilized with cisplatin-prodrug-constructed lipids enable efficient tumor oxygenation and chemo-radiotherapy of cancer

Size-Tunable Micro-Nano Liposomes: Enhanced Lung Targeting and Tumor Penetration for Combination Treatment of Lung Cancer

The inefficient delivery of nanocarriers and drug resistance seriously limit therapeutic effects of lung cancer. Here, a size-tunable micro-nano liposome system, PCAL@TM, is designed for targeted delivery of paclitaxel (PTX) and oxygen to lung tumors. PTX-loaded corosolic acid (CA) nano-liposomes (PCAL, 100 nm) are anchored to the surface of oxygenated perfluorotributylamine (TBA)-loaded multivesicular liposomes (TM, 10 µm) via the biotin-avidin interactions with matrix metalloproteinase-9 (MMP-9) cleavable linker. After intravenous administration to lung tumor-bearing mice, the distribution amount of PCAL@TM in the lungs is extremely higher than that in the liver and spleen. The MMP-9-sensitive PCAL@TM can decouple into nano-PCAL and micro-TM in tumors; while, TMs enable breaking into smaller vesicles under vascular pressure, and release oxygen leading to the downregulation of HIF-1α and platelet-activated TGF-β. Meanwhile, PCAL can penetrate deeply into tumor by the tumor-targeted-penetrable CA liposomes, to promote the reduction of inflammation levels and enhance PTX-induced immunogenic cell death (ICD). Together, these results lead to the reversals of chemoresistance and tumor immunosuppressive, achieving significant improvement in PTX chemotherapy and α-PD-1 immunotherapy. The PCAL@TM system presents a novel strategy to enhance the efficiency of nano-drug delivery and the outcome of combined therapy for lung tumor.

Research Progress in Oxygen Carrier Design and Application

Ischemia or hypoxia can lead to pathological changes in the metabolism and function of tissues and then lead to various diseases. Timely and effective blood resuscitation or improvement of hypoxia is very important for the treatment of diseases. However, there is a need to develop stable, nontoxic, and immunologically inert oxygen carriers due to limitations such as blood shortages, different blood types, and the risk of transmitting infections. With the development of various technologies, oxygen carriers based on hemoglobin and perfluorocarbon have been widely studied in recent years. This paper reviews the development and application of hemoglobin and perfluorocarbon oxygen carriers. The design of oxygen carriers was analyzed, and their application as blood substitutes or oxygen carriers in various hypoxic diseases was discussed. Finally, the characteristics and future research of ideal oxygen carriers were prospected to provide reference for follow-up research.

Prodrug Nanosensitizer Overcomes the Radiation Resistance of Hypoxic Tumor

Clinical radiation therapy (RT) is often hindered by the low radiation energy absorption coefficient and the hypoxic features of tumor tissues. Among the tremendous efforts devoted to overcoming the barriers to efficient RT, the application of hypoxic radiosensitizers and cell-cycle-specific chemotherapeutics has shown great potential. However, their effectiveness is often compromised by their limited bioavailability, especially in the hypoxic region, which plays a major role in radioresistance. Herein, to simultaneously improve the delivery efficacy of both hypoxic radiosensitizer and cell-cycle-specific drug, a gambogic acid (GA) metronidazole (MN) prodrug (GM) was designed and synthesized based on GA, a naturally occurring chemotherapeutic and multiple pathway inhibitor, and MN, a typical hypoxic radiosensitizer. In combination with MN-containing block copolymers, the prodrug nanosensitizer (NS) of GM was obtained. Owing to the bioreduction of MN, the as-designed prodrug could be efficiently delivered to hypoxic cells and act on mitochondria to cause the accumulation of reactive oxygen species. The strong G₂/M phase arrest caused by the prodrug NS could further sensitize treated cells to external radiation under hypoxic conditions by increasing DNA damage and delaying DNA repair. After coadministration of the NS with a well-established tissue-penetrating peptide, efficient tumor accumulation, deep tumor penetration, and highly potent chemoradiotherapy could be achieved.

Peroxide mediated oxygen delivery in cancer therapy

Hypoxia is a serious obstacle in cancer treatment. The aberrant vascular network as well as the abnormal extracellular matrix arrangement results in formation of a hypoxic regions in tumors which show high resistance to the curing. Hypoxia makes the cancer treatment challengeable via two mechanisms; first and foremost, hypoxia changes the cell metabolism and leads the cells towards an aggressive and metastatic phenotype and second, hypoxia decreases the efficiency of the various cancer treatment modalities. Most of the cancer treatment methods including chemotherapy, radiotherapy, photodynamic therapy, sonodynamic therapy and immunotherapy are negatively affected by the oxygen deprivation. Therefore, the regional oxygenation is requisite to alleviate the negative impacts of the hypoxia on tumor cells and tumor therapy modalities. A great deal of effort has been put forth to resolve the problem of hypoxia in tumors. Peroxides have gained tremendous attention as oxygen generating components in cancer therapy. The concurrent loading of the peroxides and cancer treatment components into a single delivery system can bring about a multipurpose delivery system and substantially encourage the success of the cancer amelioration. In this review, we have tried to after the description of a relation between hypoxia and cancer treatment modalities, discuss the role of peroxides in tumor hyperoxygenation and cancer therapy success. Thereafter, we have summarized a number of vehicles for the delivery of the peroxide alone or in combination with other therapeutic components for cancer treatment.

The Advancement of Gas-Generating Nanoplatforms in Biomedical Fields: Current Frontiers and Future Perspectives

Diverse gases (NO, CO, H₂ S, H₂ , etc.) have been widely applied in the medical intervention of various diseases, including cancer, cardiovascular disease, ischemia-reperfusion injury, bacterial infection, etc., attributing to their inherent biomedical activities. Although many gases have many biomedical activities, their clinical use is still limited due to the rapid and free diffusion behavior of these gases molecules, which may cause potential side effects and/or ineffective treatment. Gas-generating nanoplatforms (GGNs) are effective strategies to address the aforementioned challenges of gas therapy by preventing gas production or release at nonspecific sites, enhancing GGNs accumulation at targeted sites, and controlling gas release in response to exogenous (UV, NIR, US, etc.) or endogenous (H₂ O₂ , GSH, pH, etc.) stimuli at the lesion site, further maintaining gas concentration within the effective range and achieving the purpose of disease treatment. This review comprehensively summarizes the advancements of "state-of-the-art" GGNs in the recent three years, with emphasis on the composition, structure, preparation process, and gas release mechanism of the nanocarriers. Furthermore, the therapeutic effects and limitations of GGNs in preclinical studies using cell/animal models are discussed. Overall, this review enlightens the further development of this field and promotes the clinical transformation of gas therapy.

Preclinical Therapeutic Assessment of a New Chemotherapeutics [Dichloro(4,4’-Bis(2,2,3,3-Tetrafluoropropoxy) Methyl)-2,2’-Bipryridine) Platinum] in an Orthotopic Patient-Derived Xenograft Model of Triple-Negative Breast Cancers

Cisplatin is one of the most common therapeutics used in treatments of several types of cancers. To enhance cisplatin lipophilicity and reduce resistance and side effects, a polyfluorinated bipyridine-modified cisplatin analogue, dichloro[4,4’-bis(2,2,3,3-tetrafluoropropoxy)methyl)-2,2’-bipryridine] platinum (TFBPC), was synthesized and therapeutic assessments were performed. TFBPC displayed superior effects in inhibiting the proliferation of several cisplatin-resistant human cancer cell lines, including MDA-MB-231 breast cancers, COLO205 colon cancers and SK-OV-3 ovarian cancers. TFBPC bound to DNA and formed DNA crosslinks that resulted in DNA degradation, triggering the cell death program through the PARP/Bax/Bcl-2 apoptosis and LC3-related autophagy pathway. Moreover, TFBPC significantly inhibited tumor growth in both animal models which include a cell line-derived xenograft model (CDX) of cisplatin-resistant MDA-MB-231, and a patient-derived xenograft (PDX) model of triple-negative breast cancers (TNBCs). Furthermore, the biopsy specimen from TFBPC-treated xenografts revealed decreased expressions of P53, Ki-67 and PD-L1 coupled with higher expression of cleaved caspase 3, suggesting TFBPC treatment was effective and resulted in good prognostic indications. No significant pathological changes were observed in hematological and biochemistry tests in blood and histological examinations from the specimen of major organs. Therefore, TFBPC is a potential candidate for treatments of patients suffering from TNBCs as well as other cisplatin-resistant cancers.

Metallodrugs in cancer nanomedicine

Metal complexes are extensively used for cancer therapy. The multiple variables available for tuning (metal, ligand, and metal-ligand interaction) offer unique opportunities for drug design, and have led to a vast portfolio of metallodrugs that can display a higher diversity of functions and mechanisms of action with respect to pure organic structures. Clinically approved metallodrugs, such as cisplatin, carboplatin and oxaliplatin, are used to treat many types of cancer and play prominent roles in combination regimens, including with immunotherapy. However, metallodrugs generally suffer from poor pharmacokinetics, low levels of target site accumulation, metal-mediated off-target reactivity and development of drug resistance, which can all limit their efficacy and clinical translation. Nanomedicine has arisen as a powerful tool to help overcome these shortcomings. Several nanoformulations have already significantly improved the efficacy and reduced the toxicity of (chemo-)therapeutic drugs, including some promising metallodrug-containing nanomedicines currently in clinical trials. In this critical review, we analyse the opportunities and clinical challenges of metallodrugs, and we assess the advantages and limitations of metallodrug delivery, both from a nanocarrier and from a metal-nano interaction perspective. We describe the latest and most relevant nanomedicine formulations developed for metal complexes, and we discuss how the rational combination of coordination chemistry with nanomedicine technology can assist in promoting the clinical translation of metallodrugs.

Biomimetic Activator of Sonodynamic Ferroptosis Amplifies Inherent Peroxidation for Improving the Treatment of Breast Cancer

Ferroptosis is a type of nonapoptotic cell death and is gradually emerging as an important anticancer treatment. However, its therapeutic efficacy is impaired by low intracellular levels of reactive oxygen species (ROS) and long-chain polyunsaturated fatty acids, significantly limiting its therapeutic potential. Herein, a multimodal strategy to improve ferroptosis is presented, in which a state-of-art engineered erythrocyte, termed as sonodynamic amplified ferroptosis erythrocyte (SAFE), is developed for simultaneously activating ferroptosis and oxygen-riched sonodynamic therapy (SDT). SAFE is composed of internalizing RGD peptide and red blood cell membrane hybrid camouflaged nanocomplex of hemoglobin, perfluorocarbon, ferroptosis activator (dihomo-γ-linolenic acid, DGLA), and sonosensitizer verteporfin. It is identified that SAFE, under ultrasound stimulation, can not only substantially supply oxygen to overcome tumor hypoxia associated therapeutic resistance, but effectively activate ferroptosis through the coeffect of SDT triggered ROS production and DGLA mediated lipid peroxidation. In vivo studies reveal that SAFE selectively accumulates in tumor tissues and induces desirable anticancer effects under mild ultrasound stimulation. Importantly, SAFE can effectively inhibit tumor growth with minimal invasiveness, resulting in a prolonged survival period of mice. Therefore, a multimodal ferroptosis therapy driven by oxygen-riched sonodynamic peroxidation of lipids, significantly advancing synergistic cancer treatment, is presented.

Phase-shift nanodroplets as an emerging sonoresponsive nanomaterial for imaging and drug delivery applications

Nanodroplets - emerging phase-changing sonoresponsive materials - have attracted substantial attention in biomedical applications for both tumour imaging and therapeutic purposes due to their unique response to ultrasound. As ultrasound is applied at different frequencies and powers, nanodroplets have been shown to cavitate by the process of acoustic droplet vapourisation (ADV), causing the development of mechanical forces which promote sonoporation through cellular membranes. This allows drugs to be delivered efficiently into deeper tissues where tumours are located. Recent reviews on nanodroplets are mostly focused on the mechanism of cavitation and their applications in biomedical fields. However, the chemistry of the nanodroplet components has not been discussed or reviewed yet. In this review, the commonly used materials and preparation methods of nanodroplets are summarised. More importantly, this review provides examples of variable chemistry components in nanodroplets which link them to their efficiency as ultrasound-multimodal imaging agents to image and monitor drug delivery. Finally, the drawbacks of current research, future development, and future direction of nanodroplets are discussed.

Biological Utility of Fluorinated Compounds: from Materials Design to Molecular Imaging, Therapeutics and Environmental Remediation

The applications of fluorinated molecules in bioengineering and nanotechnology are expanding rapidly with the controlled introduction of fluorine being broadly studied due to the unique properties of C-F bonds. This review will focus on the design and utility of C-F containing materials in imaging, therapeutics, and environmental applications with a central theme being the importance of controlling fluorine-fluorine interactions and understanding how such interactions impact biological behavior. Low natural abundance of fluorine is shown to provide sensitivity and background advantages for imaging and detection of a variety of diseases with ¹⁹F magnetic resonance imaging, ¹⁸F positron emission tomography and ultrasound discussed as illustrative examples. The presence of C-F bonds can also be used to tailor membrane permeability and pharmacokinetic properties of drugs and delivery agents for enhanced cell uptake and therapeutics. A key message of this review is that while the promise of C-F containing materials is significant, a subset of highly fluorinated compounds such as per- and polyfluoroalkyl substances (PFAS), have been identified as posing a potential risk to human health. The unique properties of the C-F bond and the significant potential for fluorine-fluorine interactions in PFAS structures necessitate the development of new strategies for facile and efficient environmental removal and remediation. Recent progress in the development of fluorine-containing compounds as molecular imaging and therapeutic agents will be reviewed and their design features contrasted with environmental and health risks for PFAS systems. Finally, present challenges and future directions in the exploitation of the biological aspects of fluorinated systems will be described.

Combining Nanocarrier-Assisted Delivery of Molecules and Radiotherapy

Cancer is responsible for a significant proportion of death all over the world. Therefore, strategies to improve its treatment are highly desired. The use of nanocarriers to deliver anticancer treatments has been extensively investigated and improved since the approval of the first liposomal formulation for cancer treatment in 1995. Radiotherapy (RT) is present in the disease management strategy of around 50% of cancer patients. In the present review, we bring the state-of-the-art information on the combination of nanocarrier-assisted delivery of molecules and RT. We start with formulations designed to encapsulate single or multiple molecules that, once delivered to the tumor site, act directly on the cells to improve the effects of RT. Then, we describe formulations designed to modulate the tumor microenvironment by delivering oxygen or to boost the abscopal effect. Finally, we present how RT can be employed to trigger molecule delivery from nanocarriers or to modulate the EPR effect.

Light-responsive nanodrugs co-self-assembled from a PEG-Pt(IV) prodrug and doxorubicin for reversing multi-drug resistance in the chemotherapy process of hypoxic solid tumors

The hypoxia-induced multidrug resistance (MDR) often develops in the chemotherapy process of most anticancer drugs (e.g., doxorubicin, DOX) and results in the treatment failure in clinic. Herein, a PEG-Pt(IV) prodrug...

Ultrasound-augmented anti-inflammatory exosomes for targeted therapy in rheumatoid arthritis

Rheumatoid arthritis (RA), one of the systemic autoimmune diseases, features dysregulated inflammation that can eventually lead to multi-joint destruction and deformity. Although current clinical RA treatment agents including non-steroidal anti-inflammatory...

Perfluorocarbon loaded fluorinated covalent organic polymers with effective sonosensitization and tumor hypoxia relief enable synergistic sonodynamic-immunotherapy

Relieving tumor hypoxia has recently been found to be a promising approach to reverse tumor immunosuppression and thus enhance the treatment outcomes of diverse cancer treatments. Herein, we prepared a type of fluorinated covalent conjugate polymers (COPs) with sonosensitizer meso-5, 10, 15, 20-tetra (4-hydroxylphenyl) porphyrin (THPP) and perfluorosebacic acid (PFSEA) as cross-linkers, yielding THPP_pf-COPs with efficient sonodynamic efficacy and loading capacity towards perfluoro-15-crown-5-ether (PFCE), a model perfluorocarbon molecule. Upon intratumoral injection, such PFCE@THPP_pf-COPs could not only attenuate tumor hypoxia, but also exhibit the most effective suppression effect on tumor growth in the presence of ultrasound exposure by inducing immunogenic cell death of cancer cells. Furthermore, we found that the sonodynamic therapy of PFCE@THPP_pf-COPs together with anti-CD47 immunotherapy would synergistically suppress tumor growth by increasing the tumor-infiltrating frequencies of phagocytic M1 macrophages and cytotoxic CD3⁺CD8⁺ T cells, while reducing the frequency of immunosuppressive regulatory T cells. Moreover, such combination treatment could also elicit potent protective memory antitumor immunity to prevent tumor challenge. Therefore, this work presents PFCE@THPP_pf-COPs are a type of multifunctional nano-sonosensitizers potent in removing negative impacts of inherent tumor hypoxia and immunosuppression, and suppressing tumor growth and tumor recurrence by priming host's antitumor immunity, particularly in synergizing with anti-CD47 immunotherapy.

Advances of Nanomedicine in Radiotherapy

Radiotherapy (RT) remains one of the current main treatment strategies for many types of cancer. However, how to improve RT efficiency while reducing its side effects is still a large challenge to be overcome. Advancements in nanomedicine have provided many effective approaches for radiosensitization. Metal nanoparticles (NPs) such as platinum-based or hafnium-based NPs are proved to be ideal radiosensitizers because of their unique physicochemical properties and high X-ray absorption efficiency. With nanoparticles, such as liposomes, bovine serum albumin, and polymers, the radiosensitizing drugs can be promoted to reach the tumor sites, thereby enhancing anti-tumor responses. Nowadays, the combination of some NPs and RT have been applied to clinical treatment for many types of cancer, including breast cancer. Here, as well as reviewing recent studies on radiotherapy combined with inorganic, organic, and biomimetic nanomaterials for oncology, we analyzed the underlying mechanisms of NPs radiosensitization, which may contribute to exploring new directions for the clinical translation of nanoparticle-based radiosensitizers.

A co-delivery nanoplatform for a lignan-derived compound and perfluorocarbon tuning IL-25 secretion and the oxygen level in tumor microenvironments for meliorative tumor radiotherapy

A hypoxic environment in tumors hampers the therapeutic efficacy of radiotherapy. Moreover, radiotherapy, a localized treatment technique, can barely control tumor metastases. Herein, poly(lactic-co-glycolic acid) was used to encapsulate perfluorocarbon (PFC) for increasing the oxygen level and a lignan-derived compound (Q1) for enhancing IL-25 secretion from fibroblasts, thereby boosting the radiotherapeutic effect on local and distant tumors. The prepared co-delivery nanoplatform, PFC-Q1@PLGA, has a nano-scale size of around 160 nm and a negative zeta potential (about -13 mV). PFC-Q1@PLGA treatment leads to an arrest of the G2 phase (4n) in the cell cycle and reduces the mitochondria membrane potential. A high expression level of IL-25 in fibroblasts is detected after the cells are treated with PFC-Q1@PLGA, which increases the late apoptosis percentage of 4T1 cells after treatment with IL-25-containing conditional medium from fibroblasts. The oxygen level in tumors is significantly promoted to about 52.3% after injection of oxygen-saturated PFC-Q1@PLGA (O₂), which is confirmed from the functional magnetic resonance images of the tumor site in mice. The in vivo study demonstrates that the injection of PFC-Q1@PLGA (O₂) into local tumors significantly enhances the radiotherapeutic effect on local tumors and also inhibits the growth of remote tumors by an enhanced abscopal effect. This study presents a novel radiotherapy strategy to enable synergistic whole-body therapeutic responses after localized treatment with PFC-Q1@PLGA (O₂).

Functional ultrasound-triggered phase-shift perfluorocarbon nanodroplets for cancer therapy

In recent years, because of their unique properties, the use of perfluorocarbon nanodroplets (PFC NDs) in ultrasound-mediated tumor theranostics has attracted increasing interest. PFC is one of the most stable organic compounds with high hydrophobicity. Phase-shift PFC NDs can be transformed into highly echogenic microbubbles for ultrasound and photoacoustic imaging by ultrasound and laser light. In addition, in the process of acoustic droplet vaporization, PFC NDs with cavitation nuclei can be combined with a variety of ultrasound technologies to produce cavitation effects for tumor ablation, antivascular therapy and release of therapeutic agents loaded in nanodroplets. Moreover, they can also be used to overcome tumor hypoxia by virtue of high oxygen solubility. In this review, first the preparation and stabilization of PFC NDs are summarized and then the issues and outlook are discussed. More importantly, multifunctional platforms based on PFC NDs for cancer diagnostics, therapy and theranostics are reviewed in detail.

Zeolitic Imidazolate Framework Platform for Combinational Starvation Therapy and Oxygen Self-Sufficient Photodynamic Therapy against a Hypoxia Tumor

The antitumor efficacy of photodynamic therapy (PDT) is greatly impeded by the nonspecific targeting of photosensitizers and limited oxygen supply in hypoxic tumors. Aiming to overcome the problem, a dual-locked porphyrin/enzyme-loading zeolitic imidazolate framework (ZIF) nanoplatform was constructed for starvation therapy and O₂ self-sufficient PDT. The fluorescence recovery and PDT of photosensitizers could be cooperatively triggered by dual pathological parameters, the low pH and overexpressed GSH in tumor tissues, which makes the PDT process conduct precisely in a tumor microenvironment. The cascade catalysis of glucose oxidase and catalase promotes the nanoplatform dissociation, inhibits the energy supply of tumors (starvation therapy), and provides enough O₂ to ameliorate the hypoxia and enhance PDT efficacy. In vitro and in vivo studies were performed to confirm the high antitumor efficacy of the porphyrin/enzyme-loading ZIF nanoplatform. Thus, this work offers a path for precise and efficient PDT-based combination therapy against a hypoxia tumor.