Nanoparticle-mediated Photodynamic Therapy as a Method to Ablate Oral Cavity Squamous Cell Carcinoma in Preclinical Models

Photodynamic therapy (PDT) is a tissue ablation technique able to selectively target tumor cells by activating the cytotoxicity of photosensitizer dyes with light. PDT is nonsurgical and tissue sparing, two advantages for treatments in anatomically complex disease sites such as the oral cavity. We have previously developed PORPHYSOME (PS) nanoparticles assembled from chlorin photosensitizer-containing building blocks (∼94,000 photosensitizers per particle) and capable of potent PDT. In this study, we demonstrate the selective uptake and curative tumor ablation of PS-enabled PDT in three preclinical models of oral cavity squamous cell carcinoma (OCSCC): biologically relevant subcutaneous Cal-33 (cell line) and MOC22 (syngeneic) mouse models, and an anatomically relevant orthotopic VX-2 rabbit model. Tumors selectively uptake PS (10 mg/kg, i.v.) with 6-to 40-fold greater concentration versus muscle 24 hours post-injection. Single PS nanoparticle-mediated PDT (PS-PDT) treatment (100 J/cm2, 100 mW/cm2) of Cal-33 tumors yielded significant apoptosis in 65.7% of tumor cells. Survival studies following PS-PDT treatments demonstrated 90% (36/40) overall response rate across all three tumor models. Complete tumor response was achieved in 65% of Cal-33 and 91% of MOC22 tumor mouse models 14 days after PS-PDT, and partial responses obtained in 25% and 9% of Cal-33 and MOC22 tumors, respectively. In buccal VX-2 rabbit tumors, combined surface and interstitial PS-PDT (200 J total) yielded complete responses in only 60% of rabbits 6 weeks after a single treatment whereas three repeated weekly treatments with PS-PDT (200 J/week) achieved complete ablation in 100% of tumors. PS-PDT treatments were well tolerated by animals with no treatment-associated toxicities and excellent cosmetic outcomes.

SIGNIFICANCE

PS-PDT is a safe and repeatable treatment modality for OCSCC ablation. PS demonstrated tumor selective uptake and PS-PDT treatments achieved reproducible efficacy and effectiveness in multiple tumor models superior to other clinically tested photosensitizer drugs. Cosmetic and functional outcomes were excellent, and no clinically significant treatment-associated toxicities were detected. These results are enabling of window of opportunity trials for fluorescence-guided PS-PDT in patients with early-stage OCSCC scheduled for surgery.

Activatable Graphene Quantum-Dot-Based Nanotransformers for Long-Period Tumor Imaging and Repeated Photodynamic Therapy

Photodynamic therapy (PDT) is considered as an emerging therapeutic modality against cancer with high spatiotemporal selectivity because the utilized photosensitizers (PSs) are only active and toxic upon light irradiation. To maximize its effectiveness, PDT is usually applied repetitively for ablating various tumors. However, the total overdose of PSs from repeated administrations causes severe side effects. Herein, acidity-activated graphene quantum dots-based nanotransformers (GQD NT) are developed as PS vehicles for long-period tumor imaging and repeated PDT. Under the guidance of Arg-Gly-Asp peptide, GQD NT targets to tumor tissues actively, and then loosens and enlarges in tumor acidity, thus promising long tumor retention. Afterwards, GQD NT transforms into small pieces for better penetration in tumor. Upon laser irradiation, GQD NT generates mild hyperthermia that enhances cell membrane permeability and further promotes the PSs uptake. Most intriguingly, the as-prepared GQD NT not only "turns-on" fluorescence/magnetic resonance signals, but also achieves efficient repeated PDT. Notably, the total PSs dose is reduced to 3.5 µmol kg^-1 , which is 10-30 times lower than that of other reported works. Overall, this study exploits a smart vehicle to enhance accumulation, retention, and release of PSs in tumors through programmed deformation, thus overcoming the overdose obstacle in repeated PDT.

Self-Organization of Lipid-Porphyrin Conjugates at the Air/Water Interface

Lipid-porphyrin conjugates are versatile compounds which can self-assemble into liposome-like structures with multifunctional properties. Most of the conjugates that have been described so far, consisted in grafting pyropheophorbide-a (Pyro-a) or other porphyrin derivatives through the esterification of the hydroxyl group in the sn-2 position of a lysophosphatidylcholine. However, despite the versatility of these conjugates, less is known about the impact of the lipid backbone structure on their 2D phase behavior at the air/water interface and more precisely on their fine structures normal to the interface as well as on their in-plane organization. Herein, we synthesized a new lipid-porphyrin conjugate (PyroLSM) based on the amide coupling of Pyro-a to a lysosphingomyelin backbone (LSM) and we compared its interfacial behavior to that of Pyro-a and Pyro-a conjugated lysophosphatidylcholine (PyroLPC) using Langmuir balance combined to a variety of other physical techniques. Our results provided evidence on the significant impact of the lipid backbone on the lateral packing of the conjugates as well as on the shape and size of the formed domains. Compared to Pyro-a and PyroLPC monolayers, PyroLSM exhibited the highest lateral packing which highlights the role of the lipid backbone in controlling their 2D organization which in turn may impact the photophysical properties of their assemblies.

Amphiphilic Fullerene-BODIPY Photosensitizers for Targeted Photodynamic Therapy

Nanotheranostic tailor-made carriers are potent platforms for the treatment of cancer that propound a number of advantages over conventional agents for photodynamic therapy (PDT). Herein, four new heavy atom free amphiphilic glucose-BODIPY-fullerene dyads (14-17) endowed with carbohydrate units in the styryl units, which can also form nanomicelles (14-17NM) with Tween 80 for PDT are reported. Glucose-BODIPY-fullerene systems (14-17) and related nanomicelles (14-17NM) have been prepared to emcee efficient singlet oxygen generation upon light irradiation. In vitro anti-tumor effects of the compounds 14-17 and 14-17NM in the presence of light and in darkness have been investigated with K562 human chronic myelogenous leukemia suspension cells. Anti-tumor toxicity upon light irradiation was due to the formation of singlet oxygen and reactive oxygen species (ROS). This study may provide an accomplished example of efficient PDT applications based on nanovehicles fabricated with universal spin converter, fullerene, light harvesting unit, BODIPY dyes conjugated with targeting units to fight against cancer.

NIR Fluorescent Imaging and Photodynamic Therapy with a Novel Theranostic Phospholipid Probe for Triple-Negative Breast Cancer Cells

New exogenous probes are needed for both imaging diagnostics and therapeutics. Here, we introduce a novel nanocomposite near-infrared (NIR) fluorescent imaging probe and test its potency as a photosensitizing agent for photodynamic therapy (PDT) against triple-negative breast cancer cells. The active component in the nanocomposite is a small molecule, pyropheophorbide a-phosphatidylethanolamine-QSY21 (Pyro-PtdEtn-QSY), which is imbedded into lipid nanoparticles for transport in the body. The probe targets abnormal choline metabolism in cancer cells; specifically, the overexpression of phosphatidylcholine-specific phospholipase C (PC-PLC) in breast, prostate, and ovarian cancers. Pyro-PtdEtn-QSY consists of a NIR fluorophore and a quencher, attached to a PtdEtn moiety. It is selectively activated by PC-PLC resulting in enhanced fluorescence in cancer cells compared to normal cells. In our in vitro investigation, four breast cancer cell lines showed higher probe activation levels than noncancerous control cells, immortalized human mammary gland cells, and normal human T cells. Moreover, the ability of this nanocomposite to function as a sensitizer in PDT experiments on MDA-MB-231 cells suggests that the probe is promising as a theranostic agent.

Adipocyte-Derived Anticancer Lipid Droplets

Engineering of efficient and safe materials remains a challenge for cancer therapy. Here, the lipid droplet, an organelle in adipocytes, is demonstrated to be a controllable and biocompatible vehicle to deliver anticancer drugs. It is validated that isolated lipid droplets maintain their key physiological functions to interact with other organelles and augment the therapeutic effect of cancer photodynamic therapy by encapsulation with a lipid-conjugated photosensitizer (Pyrolipid) through a variety of pathways, including generation of reactive oxygen species (ROS); lipid peroxidation; and endoplasmic reticulum (ER) stress. As such, the IC50 value of Pyrolipid is reduced by 6.0-fold when loaded into the lipid droplet. Of note, in vivo results demonstrate that engineered lipid droplets induce significant inhibition of tumor growth with minimal side effects.

Porphyrin-lipid stabilized paclitaxel nanoemulsion for combined photodynamic therapy and chemotherapy

Background

Porphyrin-lipids are versatile building blocks that enable cancer theranostics and have been applied to create several multimodal nanoparticle platforms, including liposome-like porphysome (aqueous-core), porphyrin nanodroplet (liquefied gas-core), and ultrasmall porphyrin lipoproteins. Here, we used porphyrin-lipid to stabilize the water/oil interface to create porphyrin-lipid nanoemulsions with paclitaxel loaded in the oil core (PLNE-PTX), facilitating combination photodynamic therapy (PDT) and chemotherapy in one platform.

Results

PTX (3.1 wt%) and porphyrin (18.3 wt%) were loaded efficiently into PLNE-PTX, forming spherical core–shell nanoemulsions with a diameter of 120 nm. PLNE-PTX demonstrated stability in systemic delivery, resulting in high tumor accumulation (~ 5.4 ID %/g) in KB-tumor bearing mice. PLNE-PTX combination therapy inhibited tumor growth (78%) in an additive manner, compared with monotherapy PDT (44%) or chemotherapy (46%) 16 days post-treatment. Furthermore, a fourfold reduced PTX dose (1.8 mg PTX/kg) in PLNE-PTX combination therapy platform demonstrated superior therapeutic efficacy to Taxol at a dose of 7.2 mg PTX/kg, which can reduce side effects. Moreover, the intrinsic fluorescence of PLNE-PTX enabled real-time tracking of nanoparticles to the tumor, which can help inform treatment planning.

Conclusion

PLNE-PTX combining PDT and chemotherapy in a single platform enables superior anti-tumor effects and holds potential to reduce side effects associated with monotherapy chemotherapy. The inherent imaging modality of PLNE-PTX enables real-time tracking and permits spatial and temporal regulation to improve cancer treatment.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00898-1.

Tumor Microenvironment Responsive Biodegradable Fe-Doped MoOx Nanowires for Magnetic Resonance Imaging Guided Photothermal-Enhanced Chemodynamic Synergistic Antitumor Therapy

Rational design of nanosystems that target tumor microenvironment have attracted widespread attention. However, it is still a great challenge to make a multifunctional nanoplatform that actively and selectively interacts with tumor microenvironment, without causing toxicity to surrounding normal tissues. Herein, the biodegradable Fe-doped MoO_x (FMO) nanowires are designed as an anti-tumor nanoreagent that possesses great photothermal conversion ability (48.5%) and magnetic properties for T1 weighted magnetic resonance imaging (MRI). Also, FMO can be used as a chemodynamic therapy (CDT) reagent to effectively catalyze the decomposition of H₂ O₂ and produce hydroxyl radical (·OH). At the same time, the consumption of glutathione will also enhance the CDT effect. More importantly, FMO presents pH-dependent degradation behavior: rapid degradation at physiological pH, but relatively stable at acidic pH. In vivo anti-tumor experiment demonstrates that the FMO is able to effectively inhibit the tumor growth with minimal side effects. Generally speaking, these results indicate that the FMO has huge potential for MRI image-guided cancer therapy and promotes the clinical translation of nanodrugs.

Conjugated Photosensitizers for Imaging and PDT in Cancer Research

Early cancer detection and perfect understanding of the disease are imperative toward efficient treatments. It is straightforward that, for choosing a specific cancer treatment methodology, diagnostic agents undertake a critical role. Imaging is an extremely intriguing tool since it assumes a follow up to treatments to survey the accomplishment of the treatment and to recognize any conceivable repeating injuries. It also permits analysis of the disease, as well as to pursue treatment and monitor the possible changes that happen on the tumor. Likewise, it allows screening the adequacy of treatment and visualizing the state of the tumor. Additionally, when the treatment is finished, observing the patient is imperative to evaluate the treatment methodology and adjust the treatment if necessary. The goal of this review is to present an overview of conjugated photosensitizers for imaging and therapy.

Lipoprotein-Like Nanoparticle Carrying Small Interfering RNA Against Spalt-Like Transcription Factor 4 Effectively Targets Hepatocellular Carcinoma Cells and Decreases Tumor Burden

Patients with advanced hepatocellular carcinoma (HCC) are often unable to tolerate chemotherapy due to liver dysfunction in the setting of cirrhosis. We investigate high-density lipoprotein (HDL)-mimicking peptide phospholipid scaffold (HPPS), which are nanoparticles that capitalize on normal lipoprotein metabolism and transport, as a solution for directed delivery of small interfering RNA (siRNA) cargo into HCC cells. Spalt-like transcription factor 4 (SALL4), a fetal oncoprotein expressed in aggressive HCCs, is specifically targeted as a case study to evaluate the efficacy of HPPS carrying siRNA cargo. HPPS containing different formulations of siRNA therapy against SALL4 were generated specifically for HCC cells. These were investigated both in vitro and in vivo using fluorescence imaging. HPPS-SALL4 effectively bound to scavenger receptor, class B type 1 (SR-BI) and delivered the siRNA cargo into HCC cells, as seen in vitro. HPPS-SALL4 effectively inhibited HCC tumor growth (P < 0.05) and induced a 3-fold increase in apoptosis of the cancer cells in vivo compared to HPPS-scramble. Additionally, there was no immunogenicity associated with HPPS-SALL4 as measured by cytokine production. Conclusion: We have developed unique HDL-like nanoparticles that directly deliver RNA interference (RNAi) therapy against SALL4 into the cytosol of HCC cells, effectively inhibiting HCC tumor growth without any systemic immunogenicity. This therapeutic modality avoids the need for hepatic metabolism in this cancer, which develops in the setting of cirrhosis and liver dysfunction. These natural lipoprotein-like nanoparticles with RNAi therapy are a promising therapeutic strategy for HCC.

Advances in nanomaterials for photodynamic therapy applications: Status and challenges

Photodynamic therapy (PDT), as a non-invasive therapeutic modality that is alternative to radiotherapy and chemotherapy, is extensively investigated for cancer treatments. Although conventional organic photosensitizers (PSs) are still widely used and have achieved great progresses in PDT, the disadvantages such as hydrophobicity, poor stability within PDT environment and low cell/tissue specificity largely limit their clinical applications. Consequently, nano-agents with promising physicochemical and optical properties have emerged as an attractive alternative to overcome these drawbacks of traditional PSs. Herein, the up-to-date advances in the fabrication and fascinating applications of various nanomaterials in PDT have been summarized, including various types of nanoparticles, carbon-based nanomaterials, and two-dimensional nanomaterials, etc. In addition, the current challenges for the clinical use of PDT, and the corresponding strategies to address these issues, as well as future perspectives on further improvement of PDT have also been discussed.

A multifunctional liposomal nanoplatform co-delivering hydrophobic and hydrophilic doxorubicin for complete eradication of xenografted tumors

In the war against cancer, tremendous efforts have been made by using a nanoparticle-based anticancer drug system. However, it is still a great challenge to achieve complete cure and eradication of cancer through chemotherapy. Here, we present a new multifunctional liposomal nanoplatform simultaneously loaded with hydrophilic doxorubicin hydrochloride in the aqueous core and hydrophobic debydrochlorination doxorubicin in the lipid bilayer. Compared with the traditional nanoparticle-based drug delivery system, this nanocarrier has three unique functions including a high payload of the same therapeutic agents with different water-solubilities, highly selective delivery of cargos to tumor cells and long-acting time with tumors. An excellent in vitro antitumor potency can be achieved with an IC50 of 0.91 μg mL-1 for this liposome, which is only half the IC50 of free doxorubicin. More importantly, extremely good antitumor efficacy in vivo is achieved since the mean tumor volume of all xenografted tumors is respectively ∼20% and ∼10% of that of the commercial liposomal doxorubicin formulation and the single doxorubicin liposomes on day 17 after being intravenously injected with the liposome nanoformulation 4 times. Moreover, the tumors were completely cured and eradicated on day 60 with no recurrence and the survival rate still remained at 70% after 365 days. Therefore, this multifunctional binary-drug loaded liposome provides a great potential platform for winning the war against cancer.

Au Hollow Nanorods-Chimeric Peptide Nanocarrier for NIR-II Photothermal Therapy and Real-time Apoptosis Imaging for Tumor Theranostics

The strategy that combines photodynamic therapy (PDT) and photothermal therapy (PTT) is widely used to achieve strong antitumor efficiency. Since light in the NIR-II window possesses ideal penetration ability, developing NIR-II PTT and NIR-II light triggered photosensitizer release for combined PDT and PTT is very promising in nanomedicine.

Methods: We develop a novel nanocarrier (termed AuHNRs-DTPP) by conjugating photosensitizer contained chimeric peptide (DTPP) to Au hollow nanorods (AuHNRs). AuHNRs was obtained by a Te-templated method with the assistance of L-cysteine. The chimeric peptide PpIX-PEG8-GGK(TPP)GRDEVDGC (DTPP) was obtained through a solid-phase peptide synthesis (SPPS) method.

Results: Under the 1064 nm laser irradiation, the nanocarrier can accumulate heat quickly for efficient PTT, and then release activated photosensitizer for real-time apoptosis imaging. Thereafter, supplementary PDT can be conducted to kill tumor cells survived from the PTT, and meanwhile the normal tissue can be protected from photo-toxicity.

Conclusion: This designed AuHNRs-DTPP nanocarrier with remarkable therapy effect, real-time apoptosis imaging ability and reduced skin damage is of great potential in nanomedicine application.

Strategies for Image-Guided Therapy, Surgery, and Drug Delivery Using Photoacoustic Imaging

Photoacoustic imaging is a rapidly maturing imaging modality in biological research and medicine. This modality uses the photoacoustic effect ("light in, sound out") to combine the contrast and specificity of optical imaging with the high temporal resolution of ultrasound. The primary goal of image-guided therapy, and theranostics in general, is to transition from conventional medicine to precision strategies that combine diagnosis with therapy. Photoacoustic imaging is well-suited for noninvasive guidance of many therapies and applications currently being pursued in three broad areas. These include the image-guided resection of diseased tissue, monitoring of disease states, and drug delivery. In this review, we examine the progress and strategies for development of photoacoustics in these three key areas with an emphasis on the value photoacoustics has for image-guided therapy.

Photothermal-Triggered Shape Memory Polymer Prepared by Cross-Linking Porphyrin-Loaded Micellar Particles

In this work, we fabricated porphyrin-loaded shape memory polymer (SMP) film by cross-linking micellar particles prepared by co-assembly of porphyrin compounds and amphiphilic macromolecules formulated by copolymerization of 2-butoxy ethanol (BCS), methyl methacrylate (MMA), butyl acrylate (BA) acrylic acid (AA), and diacetone acrylamide (DAAM). The experimental results revealed that this film was able to respond to the red light in terms of photothermal effect enabled by the porphyrin filler. The photothermal-triggered shape memory behaviors of the film were further examined in detail. It was noteworthy that this material was expected to have potential applications in the biomedical field due to the excellent biocompatibility of the porphyrin filler and the red-light source, which was optimal and safe enough for biomedical treatment.

Metalloporphyrin Nanoparticles: Coordinating Diverse Theranostic Functions

Metalloporphyrins serve key roles in natural biological processes and also have demonstrated utility for biomedical applications. They can be encapsulated or grafted in conventional nanoparticles or can self-assemble themselves at the nanoscale. A wide range of metals can be stably chelated either before or after porphyrin nanoparticle formation, without the necessity of any additional chelator chemistry. The addition of metals can substantially alter a range of behaviors such as modulating phototherapeutic efficacy; conferring responsiveness to biological stimuli; or providing contrast for magnetic resonance, positron emission or surface enhanced Raman imaging. Chelated metals can also provide a convenient handle for bioconjugation with other molecules via axial coordination. This review provides an overview of some recent biomedical, nanoparticulate approaches involving gain-of-function metalloporphyrins and related molecules.

Drug-Controlled Release Based on Complementary Base Pairing Rules for Photodynamic-Photothermal Synergistic Tumor Treatment

Controlled drug release systems can enhance the safety and availability but avoid the side effect of drugs. Herein, the concept of DNA complementary base pairing rules in biology is used to design and prepare a photothermal-triggered drug release system. Adenine (A) modified polydopamine nanoparticles (A-PDA, photothermal reagent) can effectively bind with thymine (T) modified Zinc phthalocyanine (T-ZnPc, photosensitizer) forming A-PDA = T-ZnPc (PATP) complex based on A = T complementary base pairing rules. Similar to DNA, whose base pairing in double strands will break by heating, T-ZnPc can be effectively released from A-PDA after near infrared irradiation-triggered light-thermal conversion to obtain satisfactory photodynamic-photothermal synergistic tumor treatment. In addition, PDA can carry abundant Gd³⁺ to provide magnetic resonance imaging guided delivery and theranostic function.

Molybdenum oxide nano-dumplings with excellent stability for photothermal cancer therapy and as a controlled release hydrogel

MoO_3−x is synthesized via a one-pot hydrothermal method, with excellent stability against aging, heat, laser exposure and chemical etching.

Preclinical investigation of folate receptor-targeted nanoparticles for photodynamic therapy of malignant pleural mesothelioma

Photodynamic therapy (PDT) following lung-sparing extended pleurectomy for malignant pleural mesothelioma (MPM) has been investigated as a potential means to kill residual microscopic cells. High expression levels of folate receptor 1 (FOLR1) have been reported in MPM; therefore, targeting FOLR1 has been considered a novel potential strategy. The present study developed FOLR1‑targeting porphyrin-lipid nanoparticles (folate-porphysomes, FP) for the treatment of PDT. Furthermore, inhibition of activated epidermal growth factor (EGFR)-associated survival pathways enhance PDT efficacy. In the present study, these approaches were combined; FP-based PDT was used together with an EGFR-tyrosine kinase inhibitor (EGFR-TKI). The frequency of FOLR1 and EGFR expression in MPM was analyzed using tissue microarrays. Confocal microscopy and a cell viability assay were performed to confirm the specificity of FOLR1‑targeting cellular uptake and photocytotoxicity in vitro. In vivo fluorescence activation and therapeutic efficacy were subsequently examined. The effects of EGFR-TKI were also assessed in vitro. The in vivo combined antitumor effect of EGFR-TKI and FP-PDT was then evaluated. The results revealed that FOLR1 and EGFR were expressed in 79 and 89% of MPM samples, respectively. In addition, intracellular uptake of FP corresponded well with FOLR1 expression. When MPM cells were incubated with FP and then irradiated at 671 nm, there was significant in vitro cell death, which was inhibited in the presence of free folic acid, thus suggesting the specificity of FPs. FOLR1 targeting resulted in disassembly of the porphysomes and subsequent fluorescence activation in intrathoracic disseminated MPM tumors, as demonstrated by ex vivo tissue imaging. FP-PDT resulted in significant cellular damage and apoptosis in vivo. Furthermore, the combination of pretreatment with EGFR-TKI and FP-PDT induced a marked improvement of treatment responses. In conclusion, FP-based PDT induced selective destruction of MPM cells based on FOLR1 targeting, and pretreatment with EGFR-TKI further enhanced the therapeutic response.

Photodynamic therapy: Promoting in vitro efficacy of photodynamic therapy by liposomal formulations of a photosensitizing agent

OBJECTIVE

A relatively low level of lysosomal photodamage has been shown capable of promoting the efficacy of photodamage simultaneously or subsequently directed to mitochondrial/ER sites. The procedure has hitherto involved the use of two photosensitizing agents that require irradiation at two different wavelengths and different formulation techniques. This, together with different pharmacokinetic profiles of the photosensitizers, adds a layer of complexity to a protocol that we have sought to circumvent. In this study, liposomal formulations were used to direct photodamage created by benzoporphyrin derivative (BPD, Verteporfin) to lysosomes, mitochondria and the ER. This resulted in the development of an optimal targeting profile using a single agent and a single wavelength of activating irradiation.

MATERIALS/METHODS

These studies were carried out in monolayer cultures of OVCAR5 tumor cells. BPD localization was modified by lipid anchoring and formulation in liposomes, and was assessed by fluorescence microscopy. Irradiation was carried out at 690 ± 10 nm with photodamage assessed also using fluorescent probes and microscopy.

RESULTS

BPD normally localizes in a wide variety of sub-cellular loci that include both mitochondria and the ER, but lysosomes are spared from photodamage. Using a liposomal formulation containing BPD anchored to a lipid resulted in the targeting of lysosomes. A mixture of liposomes containing "free" and "anchored" BPD was shown to significantly promote photokilling. Eliminating cholesterol from the formulation of the anchored product enhanced lysosomal photodamage; prior studies had revealed that excess cholesterol can have a cytoprotective effect when lysosomes are the PDT target.

DISCUSSION

The ability of a liposomal formulation to change localization patterns permits directing photodynamic therapy toward specific sub-cellular loci, thereby promoting photokilling. Incorporating chemotherapeutic agents into such formulations could represent a logical next step in assessing the ability of directed photodamage to enhance tumor eradication. Lasers Surg. Med. 50:499-505, 2018. © 2018 Wiley Periodicals, Inc.

Selectively Inducing Cancer Cell Death by Intracellular Enzyme-Instructed Self-Assembly (EISA) of Dipeptide Derivatives

Tight ligand-receptor binding, paradoxically, is a major root of drug resistance in cancer chemotherapy. To address this problem, instead of using conventional inhibitors or ligands, this paper focuses on the development of a novel process-enzyme-instructed self-assembly (EISA)-to kill cancer cells selectively. Here it is demonstrated that EISA as an intracellular process to generate nanofibrils of short peptides for selectively inhibiting cancer cell proliferation, including drug resistant ones. As the process that turns the non-self-assembling precursors into the self-assembling peptides upon the catalysis of carboxylesterases (CES), EISA occurs intracellularly to selectively inhibit a range of cancer cells that exhibit relatively high CES activities. More importantly, EISA inhibits drug resistant cancer cells (e.g., triple negative breast cancer cells (HCC1937) and platinum-resistant ovarian cells (SKOV3, A2780cis)). With the IC50 values of 28-80 and 25-44 µg mL-1 of l- and d-dipeptide precursors against cancer cells, respectively, EISA is innocuous to normal cells. Moreover, using coculture of cancer and normal cells, the selectivity of EISA is validated against cancer cells. Besides revealing that intracellular EISA cause apoptosis or necroptosis to kill the cancer cells, this work illustrates a new approach to amplify the enzymatic difference between cancer and normal cells and to expand the pool of drug candidates for potentially overcoming drug resistance in cancer therapy.

Activatable fluorescence: From small molecule to nanoparticle

Molecular imaging has emerged as an indispensable technology in the development and application of drug delivery systems. Targeted imaging agents report the presence of biomolecules, including therapeutic targets and disease biomarkers, while the biological behaviour of labelled delivery systems can be non-invasively assessed in real time. As an imaging modality, fluorescence offers additional signal specificity and dynamic information due to the inherent responsivity of fluorescence agents to interactions with other optical species and with their environment. Harnessing this responsivity is the basis of activatable fluorescence imaging, where interactions between an engineered fluorescence agent and its biological target induce a fluorogenic response. Small molecule activatable agents are frequently derivatives of common fluorophores designed to chemically react with their target. Macromolecular scale agents are useful for imaging proteins and nucleic acids, although their biological delivery can be difficult. Nanoscale activatable agents combine the responsivity of fluorophores with the unique optical and physical properties of nanomaterials. The molecular imaging application and overall complexity of biological target dictate the most advantageous fluorescence agent size scale and activation strategy.

Multifunctional Theranostic Agent of Cu2(OH)PO4 Quantum Dots for Photoacoustic Image-Guided Photothermal/Photodynamic Combination Cancer Therapy

Image-guided phototherapy is considered to be a prospective technique for cancer treatment because it can provide both oncotherapy and bioimaging, thus achieving an optimized therapeutic efficacy and higher treatment accuracy. Compared to complicated systems with multiple components, using a single material for this multifunctional purpose is preferable. In this work, we strategically fabricated poly(acrylic acid)- (PAA-) coated Cu₂(OH)PO₄ quantum dots [denoted as Cu₂(OH)PO₄@PAA QDs], which exhibit a strong near-infrared photoabsorption ability. As a result, an excellent photothermal conversion ability and the photoactivated formation of reactive oxygen species could be realized upon NIR irradiation, concurrently meeting the basic requirements for photothermal and photodynamic therapies. Moreover, phototherapeutic investigations on both cervical cancer cells in vitro and solid tumors of an in vivo mice model illustrated the effective antitumor effects of Cu₂(OH)PO₄@PAA upon 1064-nm laser irradiation, with no detectable lesions in major organs during treatment. Meanwhile, Cu₂(OH)PO₄@PAA is also an exogenous contrast for photoacoustic tomography (PAT) imaging to depict tumors under NIR irradiation. In brief, the Cu₂(OH)PO₄@PAA QDs prepared in this work are expected to serve as a multifunctional theranostic platform.

MoO3-x quantum dots for photoacoustic imaging guided photothermal/photodynamic cancer treatment

A theranostic system of image-guided phototherapy is considered as a potential technique for cancer treatment because of the ability to integrate diagnostics and therapies together, thus enhancing accuracy and visualization during the treatment. In this work, we realized photoacoustic (PA) imaging-guided photothermal (PT)/photodynamic (PD) combined cancer treatment just via a single material, MoO_3-x quantum dots (QDs). Due to their strong NIR harvesting ability, MoO_3-x QDs can convert incident light into hyperthermia and sensitize the formation of singlet oxygen synchronously as evidenced by in vitro assay, hence, they can behave as both PT and PD agents effectively and act as a "dual-punch" to cancer cells. In a further study, elimination of solid tumors from HeLa-tumor bearing mice could be achieved in a MoO_3-x QD mediated phototherapeutic group without obvious lesions to the major organs. In addition, the desired PT effect also makes MoO_3-x QDs an exogenous PA contrast agent for in vivo live-imaging to depict tumors. Compared with previously reported theranostic systems that put several components into one system, our multifunctional agent of MoO_3-x QDs is exempt from unpredictable mutual interference between components and ease of leakage of virtual components from the composited system.

Advanced Functional Nanomaterials for Theranostics

Nanoscale materials have been explored extensively as agents for therapeutic and diagnostic (i.e. theranostic) applications. Research efforts have shifted from exploring new materials in vitro to designing materials that function in more relevant animal disease models, thereby increasing potential for clinical translation. Current interests include non-invasive imaging of diseases, biomarkers and targeted delivery of therapeutic drugs. Here, we discuss some general design considerations of advanced theranostic materials and challenges of their use, from both diagnostic and therapeutic perspectives. Common classes of nanoscale biomaterials, including magnetic nanoparticles, quantum dots, upconversion nanoparticles, mesoporous silica nanoparticles, carbon-based nanoparticles and organic dye-based nanoparticles, have demonstrated potential for both diagnosis and therapy. Variations such as size control and surface modifications can modulate biocompatibility and interactions with target tissues. The needs for improved disease detection and enhanced chemotherapeutic treatments, together with realistic considerations for clinically translatable nanomaterials will be key driving factors for theranostic agent research in the near future.

Csx WO3 Nanorods Coated with Polyelectrolyte Multilayers as a Multifunctional Nanomaterial for Bimodal Imaging-Guided Photothermal/Photodynamic Cancer Treatment

Cs_x WO₃ nanorods coated with polyelectrolyte multilayers are developed as "four-in-one" multifunctional nanomaterials with significant potential for computed tomography/photoacoustic tomography bimodal imaging-guided photothermal/photodynamic cancer treatment.

Donor–acceptor type A2B2porphyrins: synthesis, energy transfer, computational and electrochemical studies

Synthesis, photophysical, electrochemical and DFT studies of donor–acceptor type A₂B₂porphyrins and their Zn(ii) and Pd(ii) complexes have been described.

Design of Hydrated Porphyrin-Phospholipid Bilayers with Enhanced Magnetic Resonance Contrast

Computer simulations are used to design more hydrated bilayers, formed from amine-modified porphyrin-phospholipids (PoPs). Experiments confirm that the new constructs give rise to bilayers with greater water content. When chelated with manganese, amine-modified PoPs provide improved contrast for magnetic resonance and are safely used for imaging in vivo.

Combination of Fluorescence-Guided Surgery With Photodynamic Therapy for the Treatment of Cancer

Specific visualization of body parts is needed during surgery. Fluorescence-guided surgery (FGS) uses a fluorescence contrast agent for in vivo tumor imaging to detect and identify both malignant and normal tissues. There are several advantages and clinical benefits of FGS over other conventional medical imaging modalities, such as its safety, effectiveness, and suitability for real-time imaging in the operating room. Recent advancements in contrast agents and intraoperative fluorescence imaging devices have led to a greater potential for intraoperative fluorescence imaging in clinical applications. Photodynamic therapy (PDT) is an alternative modality to treat tumors, which uses a light-sensitive drug (photosensitizers) and special light to destroy the targeted tissues. In this review, we discuss the fluorescent contrast agents, some newly developed imaging devices, and the successful clinical application of FGS. Additionally, we present the combined strategy of FGS with PDT to further improve the therapeutic effect for patients with cancer. Taken together, this review provides a unique perspective and summarization of FGS.

Synthesis and in vitro antioxidant and antimicrobial studies of novel structured phosphatidylcholines with phenolic acids

Novel phenoylated phosphatidylcholines were synthesized from 1,2-dipalmitoyl phosphatidylcholine/egg 1,2-diacyl phosphatidylcholine and phenolic acids such as ferulic, sinapic, vanillic and syringic acids. The structures of phenoylated phosphatidylcholines were confirmed by spectral analysis. 2-acyl-1-lyso phosphatidylcholine was synthesized from phosphatidylcholine via regioselective enzymatic hydrolysis and was reacted with hydroxyl protected phenolic acids to produce corresponding phenoylated phosphatidylcholines in 48-56% yields. Deprotection of protected phenoylated phosphatidylcholines resulted in phenoylated phosphatidylcholines in 87-94% yields. The prepared compounds were evaluated for their preliminary in vitro antimicrobial and antioxidant activities. Among the active derivatives, compound 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine exhibited excellent antioxidant activity with EC₅₀ value of 16.43μg/mL. Compounds 1-(4-hydroxy-3-methoxy) cinnamoyl-2-acyl-sn-glycero-3-phosphocholine and 1-(4-hydroxy-3,5-dimethoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antioxidant activity with EC₅₀ values of 36.05 and 33.35μg/mL respectively. Compound 1-(4-hydroxy-3-methoxy) cinnamoyl-2-palmitoyl-sn-glycero-3-phosphocholine exhibited good antibacterial activity against Klebsiella planticola with MIC of 15.6μg/mL and compound 1-(4-hydroxy-3-methoxy) benzoyl-2-acyl-sn-glycero-3-phosphocholine exhibited good antifungal activity against Candida albicans with MIC of 15.6μg/mL.

Recent Advances of Light-Mediated Theranostics

Currently, precision theranostics have been extensively demanded for the effective treatment of various human diseases. Currently, efficient therapy at the targeted disease areas still remains challenging since most available drug molecules lack of selectivity to the pathological sites. Among different approaches, light-mediated therapeutic strategy has recently emerged as a promising and powerful tool to precisely control the activation of therapeutic reagents and imaging probes in vitro and in vivo, mostly attributed to its unique properties including minimally invasive capability and highly spatiotemporal resolution. Although it has achieved initial success, the conventional strategies for light-mediated theranostics are mostly based on the light with short wavelength (e.g., UV or visible light), which may usually suffer from several undesired drawbacks, such as limited tissue penetration depth, unavoidable light absorption/scattering and potential phototoxicity to healthy tissues, etc. Therefore, a near-infrared (NIR) light-mediated approach on the basis of long-wavelength light (700-1000 nm) irradiation, which displays deep-tissue penetration, minimized photo-damage and low autofluoresence in living systems, has been proposed as an inspiring alternative for precisely phototherapeutic applications in the last decades. Despite numerous NIR light-responsive molecules have been currently proposed for clinical applications, several inherent drawbacks, such as troublesome synthetic procedures, low water solubility and limited accumulation abilities in targeted areas, heavily restrict their applications in deep-tissue therapeutic and imaging studies. Thanks to the amazing properties of several nanomaterials with large extinction coefficient in the NIR region, the construction of NIR light responsive nanoplatforms with multifunctions have become promising approaches for deep-seated diseases diagnosis and therapy. In this review, we summarized various light-triggered theranostic strategies and introduced their great advances in biomedical applications in recent years. Moreover, some other promising light-assisted techniques, such as photoacoustic and Cerenkov radiation, were also systemically discussed. Finally, the potential challenges and future perspectives for light-mediated deep-tissue diagnosis and therapeutics were proposed.

Sphingomyelin Liposomes Containing Porphyrin-phospholipid for Irinotecan Chemophototherapy

Porphyrin-phospholipid (PoP) liposomes can entrap anti-cancer agents and release them in response to near infrared (NIR) light. Doxorubicin, when remotely loaded via an ammonium sulfate gradient at a high drug-to-lipid ratio, formed elongated crystals that altered liposome morphology and could not be loaded into liposomes with higher PoP content. On the other hand, irinotecan could also be remotely loaded but did not form large crystals and did not induce liposome elongation. The loading, stability, and NIR light-triggered release of irinotecan in PoP liposomes was altered by the types of lipids used and the presence of PEGylation. Sphingomyelin, which has been explored previously for liposomal irinotecan, was found to produce liposomes with relatively improved serum stability and rapid NIR light-triggered drug release. PoP liposomes composed from sphingomyelin, cholesterol and 2 molar percent PoP rapidly released irinotecan in vivo in response to NIR irradiation as monitored by intravital microscopy and also induced effective tumor eradication in mice bearing MIA Paca-2 subcutaneous tumor xenografts.

Nanoparticle-Enabled Selective Destruction of Prostate Tumor Using MRI-Guided Focal Photothermal Therapy

BACKGROUND

The Magnetic Resonance Imaging (MRI)-guided focal laser therapy has shown early promise in Phase 1 trial treating low/intermediate-risk localized prostate cancer (PCa), but the lack of tumor selectivity and low efficiency of heat generation remain as drawbacks of agent-free laser therapy. Intrinsic multifunctional porphyrin-nanoparticles (porphysomes) have been exploited to treat localized PCa by MRI-guided focal photothermal therapy (PTT) with significantly improved efficiency and tumor selectivity over prior methods of PTT, providing an effective and safe alternative to active surveillance or radical therapy.

METHODS

The tumor accumulation of porphysomes chelated with copper-64 was determined and compared with the clinic standard (18) F-FDG in an orthotropic PCa mouse model by positron emission tomography (PET) imaging, providing quantitative assessment for PTT dosimetry. The PTT was conducted with MRI-guided light delivery and monitored by MR thermometry, mimicking the clinical protocol. The efficacy of treatment and adverse effects to surround tissues were evaluated by histology analysis and tumor growth in survival study via MRI.

RESULTS

Porphysomes showed superior tumor-to-prostate selectivity over (18) F-FDG (6:1 vs. 0.36:1). MR thermometry detected tumor temperature increased to ≥55°C within 2 min (671 nm at 500 mW), but minimal increase in surrounding tissues. Porphysome enabled effective PTT eradication of tumor without damaging adjacent organs in orthotropic PCa mouse model.

CONCLUSIONS

Porphysome-enabled MRI-guided focal PTT could be an effective and safe approach to treat PCa at low risk of progression, thus addressing the significant unmet clinical needs and benefiting an ever-growing number of patients who may be over-treated and risk unnecessary side effects from radical therapies. Prostate 76:1169-1181, 2016. © 2016 Wiley Periodicals, Inc.

Advances in biodegradable nanomaterials for photothermal therapy of cancer

Photothermal cancer therapy is an alternative to chemotherapy, radiotherapy, and surgery. With the development of nanophotothermal agents, this therapy holds immense potential in clinical translation. However, the toxicity issues derived from the fact that nanomaterials are trapped and retained in the reticuloendothelial systems limit their biomedical application. Developing biodegradable photothermal agents is the most practical route to address these concerns. In addition to the physicochemical properties of nanomaterials, various internal and external stimuli play key roles on nanomaterials uptake, transport, and clearance. In this review, we summarized novel nanoplatforms for photothermal therapy; these nanoplatforms can elicit stimuli-triggered degradation. We focused on the recent innovative designs endowed with biodegradable photothermal agents under different stimuli, including enzyme, pH, and near-infrared (NIR) laser.

Core-shell nanoscale coordination polymers combine chemotherapy and photodynamic therapy to potentiate checkpoint blockade cancer immunotherapy

Advanced colorectal cancer is one of the deadliest cancers, with a 5-year survival rate of only 12% for patients with the metastatic disease. Checkpoint inhibitors, such as the antibodies inhibiting the PD-1/PD-L1 axis, are among the most promising immunotherapies for patients with advanced colon cancer, but their durable response rate remains low. We herein report the use of immunogenic nanoparticles to augment the antitumour efficacy of PD-L1 antibody-mediated cancer immunotherapy. Nanoscale coordination polymer (NCP) core-shell nanoparticles carry oxaliplatin in the core and the photosensitizer pyropheophorbide-lipid conjugate (pyrolipid) in the shell (NCP@pyrolipid) for effective chemotherapy and photodynamic therapy (PDT). Synergy between oxaliplatin and pyrolipid-induced PDT kills tumour cells and provokes an immune response, resulting in calreticulin exposure on the cell surface, antitumour vaccination and an abscopal effect. When combined with anti-PD-L1 therapy, NCP@pyrolipid mediates regression of both light-irradiated primary tumours and non-irradiated distant tumours by inducing a strong tumour-specific immune response.

Blockade of PD-L1 is usually not very effective in colon cancer patients. Here, the authors show the efficacy of PD-L1 blockade in combination with coordination polymer nanoparticles carrying oxaliplatin and a photosensitizer to induce anti-tumor immunity in metastatic models of colon cancer.

Photonanomedicine: a convergence of photodynamic therapy and nanotechnology

As clinical nanomedicine has emerged over the past two decades, phototherapeutic advancements using nanotechnology have also evolved and impacted disease management. Because of unique features attributable to the light activation process of molecules, photonanomedicine (PNM) holds significant promise as a personalized, image-guided therapeutic approach for cancer and non-cancer pathologies. The convergence of advanced photochemical therapies such as photodynamic therapy (PDT) and imaging modalities with sophisticated nanotechnologies is enabling the ongoing evolution of fundamental PNM formulations, such as Visudyne®, into progressive forward-looking platforms that integrate theranostics (therapeutics and diagnostics), molecular selectivity, the spatiotemporally controlled release of synergistic therapeutics, along with regulated, sustained drug dosing. Considering that the envisioned goal of these integrated platforms is proving to be realistic, this review will discuss how PNM has evolved over the years as a preclinical and clinical amalgamation of nanotechnology with PDT. The encouraging investigations that emphasize the potent synergy between photochemistry and nanotherapeutics, in addition to the growing realization of the value of these multi-faceted theranostic nanoplatforms, will assist in driving PNM formulations into mainstream oncological clinical practice as a necessary tool in the medical armamentarium.

Porphyrin-loaded nanoparticles for cancer theranostics

Porphyrins have been used as pioneering theranostic agents not only for the photodynamic therapy, sonodynamic therapy and radiotherapy of cancer, but also for diagnostic fluorescence imaging, magnetic resonance imaging and photoacoustic imaging. A variety of porphyrins have been developed but very few of them have actually been employed in clinical trials due to their poor selectivity to tumorous tissue and high accumulation rates in the skin. In addition, most porphyrin molecules are hydrophobic and form aggregates in aqueous media. Nevertheless, the use of nanoparticles as porphyrin carriers shows great promise to overcome these shortcomings. Encapsulating or attaching porphyrins to nanoparticles makes them more suitable for tissue delivery because we can create materials with a conveniently specific tissue lifetime, specific targeting, immune tolerance, and hydrophilicity as well as other characteristics through rational design. In addition, various functional components (e.g. for targeting, imaging or therapeutic functions) can be easily introduced into a single nanoparticle platform for cancer theranostics. This review presents the current state of knowledge on porphyrin-loaded nanoparticles for the interwined imaging and therapy of cancer. The future trends and limitations of prophyrin-loaded nanoparticles are also outlined.

Rethinking translational nanomedicine: insights from the 'bottom-up' design of the Porphysome for guiding the clinical development of imageable nanomaterials

Progress in therapeutics and biotechnologies leveraging new insights in our understanding of cancer biology and progression have had an underwhelming clinical significance thus far. A key challenge arising from the creation of nanomedicines consolidating multiple desirable functionalities into a 'all-in-one' platform is that the layering of functionalities into a single agent introduces novel complexities that significantly impede clinical translation. An alternative design approach seeks to exploit intrinsically multi-functional building block to assemble nanomedicines from the bottom-up, yielding agents with a multiplicity of radiologic, pharmacologic, and therapeutic properties derived from a single constituent. Herein are highlighted recent developments in the formulation, multi-modal imaging, and targeting of an exemplary 'one-for-all' nanomaterial-the Pyropheophorbide Porphysome-treated from a hitherto unexplored clinical design and development perspective.

Fullerene/photosensitizer nanovesicles as highly efficient and clearable phototheranostics with enhanced tumor accumulation for cancer therapy

A novel phototheranostic platform based on tri-malonate derivative of fullerene C70 (TFC70)/photosensitizer (Chlorin e6, Ce6) nanovesicles (FCNVs) has been developed for effective tumor imaging and treatment. The FCNVs were prepared from amphiphilic TFC70-oligo ethylene glycol -Ce6 molecules. The developed FCNVs possessed the following advantages: (i) high loading efficiency of Ce6 (up to ∼57 wt%); (ii) efficient absorption in near-infrared light region; (iii) enhanced cellular uptake efficiency of Ce6 in vitro and in vivo; (iv) good biocompatibility and total clearance out from the body. These unique properties suggest that the as-prepared FCNVs could be applied as an ideal theranostic agent for simultaneous imaging and photodynamic therapy of tumor. This finding may provide a good solution to highly efficient phototheranostic applications based on fullerene derivatives fabricated nanostructures.

Opportunities for Photoacoustic-Guided Drug Delivery

Photoacoustic imaging (PAI) is rapidly becoming established as a viable imaging modality for small animal research, with promise of near-future human clinical translation. In this review, we discuss emerging prospects for photoacoustic-guided drug delivery. PAI presents opportunities for applications related to drug delivery, mainly with respect to either monitoring drug effects or monitoring drugs themselves. PAI is well-suited for imaging disease pathology and treatment response. Alternatively, PAI can be used to directly monitor the accumulation of various light-absorbing contrast agents or carriers with theranostic properties.

Chlorosome-Inspired Synthesis of Templated Metallochlorin-Lipid Nanoassemblies for Biomedical Applications

Chlorosomes are vesicular light-harvesting organelles found in photosynthetic green sulfur bacteria. These organisms thrive in low photon flux environments due to the most efficient light-to-chemical energy conversion, promoted by a protein-less assembly of chlorin pigments. These assemblies possess collective absorption properties and can be adapted for contrast-enhanced bioimaging applications, where maximized light absorption in the near-infrared optical window is desired. Here, we report a strategy for tuning light absorption toward the near-infrared region by engineering a chlorosome-inspired assembly of synthetic metallochlorins in a biocompatible lipid scaffold. In a series of synthesized chlorin analogues, we discovered that lipid conjugation, central coordination of a zinc metal into the chlorin ring, and a 3(1)-methoxy substitution were critical for the formation of dye assemblies in lipid nanovesicles. The substitutions result in a specific optical shift, characterized by a bathochromically shifted (72 nm) Qy absorption band, along with an increase in absorbance and circular dichroism as the ratio of dye-conjugated lipid was increased. These alterations in optical spectra are indicative of the formation of delocalized excitons states across each molecular assembly. This strategy of tuning absorption by mimicking the structures found in photosynthetic organisms may spur new opportunities in the development of biophotonic contrast agents for medical applications.

Multimodal micro, nano, and size conversion ultrasound agents for imaging and therapy

Ultrasound (US) is one of the most commonly used clinical imaging techniques. However, the use of US and US-based intravenous agents extends far beyond imaging. In particular, there has been a surge in the fabrication of multimodality US contrast agents and theranostic US agents for cancer imaging and therapy. The unique interaction of US waves with microscale and nanoscale agents has attracted much attention in the development of contrast agents and drug-delivery vehicles. The dimensions of the agent not only dictate how it behaves in vivo, but also how it interacts with US for imaging and drug delivery. Furthermore, these agents are also unique due to their ability to convert from the nanoscale to the microscale and vice versa, having imaging and therapeutic utility in both dimensions. Here, we review multimodality and multifunctional US-based agents, according to their size, and also highlight recent developments in size conversion US agents. WIREs Nanomed Nanobiotechnol 2016, 8:796-813. doi: 10.1002/wnan.1398 For further resources related to this article, please visit the WIREs website.

Photothermal and photodynamic therapy reagents based on rGO–C6H4–COOH

A photothermal and photodynamic therapy reagent based on rGO–C₆H₄–COOH was developed, which could effectively induce cancer cell apoptosis.

Hybrid nanoparticles for combination therapy of cancer

Nanoparticle anticancer drug delivery enhances therapeutic efficacies and reduces side effects by improving pharmacokinetics and biodistributions of the drug payloads in animal models. Despite promising preclinical efficacy results, monotherapy nanomedicines have failed to produce enhanced response rates over conventional chemotherapy in human clinical trials. The discrepancy between preclinical data and clinical outcomes is believed to result from the less pronounced enhanced permeability and retention (EPR) effect in and the heterogeneity of human tumors as well as the intrinsic/acquired drug resistance to monotherapy over the treatment course. To address these issues, recent efforts have been devoted to developing nanocarriers that can efficiently deliver multiple therapeutics with controlled release properties and increased tumor deposition. In ideal scenarios, the drug or therapeutic modality combinations have different mechanisms of action to afford synergistic effects. In this review, we summarize recent progress in designing hybrid nanoparticles for the co-delivery of combination therapies, including multiple chemotherapeutics, chemotherapeutics and biologics, chemotherapeutics and photodynamic therapy, and chemotherapeutics and radiotherapy. The in vitro and in vivo anticancer effects are also discussed.