Tumor-Cell-Surface Adherable Peptide-Drug Conjugate Prodrug Nanoparticles Inhibit Tumor Metastasis and Augment Treatment Efficacy

Recent progress in the development of peptide-drug conjugates (PDCs) for cancer therapy

Peptide-drug conjugates (PDCs) are emerging therapeutic agents composed of peptides, linkers, and payloads, which possess favorable targeting capability and can deliver enough payloads to the tumor sites with minimized impact on healthy tissues. However, only a few PDCs have been approved for clinical use so far. To advance the research on PDCs, this review summarizes the approved PDCs, and PDCs in clinical and preclinical stages based on the payload types. Additionally, the biological activity and pharmacokinetic properties of preclinical PDCs are detailedly described. Lastly, the challenges and future development directions of PDCs are discussed. This review aims to inspire insights into the development of PDCs for cancer treatment.

Synergistic Target-Attacking Tumor Cells and M2 Macrophages via a Triple-Responsive Nanoassembly for Complete Metastasis Blocking

Collaboration of cancerous cells and microenvironment is the root for tumor spreading, leading to difficulty in complete metastasis blockage via mono-intervention. Herein, a triple-responsive nanoassembly is designed for orienting tumor cells and migration-driving M2 tumor associated macrophages (TAMs) in microenvironment for efficient anti-metastatic therapy. Structurally, a reactive oxygen species (ROS)-responsive crosslinked short-chain polyquaternium is synthesized to bridge graphene oxide (GO) scaffold with apolipoprotein A-I crown via borate-crosslinking, electrostatic adherence, and coordinative coupling. The protein-crowning polymeric GO nanoparticles could give multimodal shielding and triple-responsive release of doxorubicin and Snail-targeted siRNA. Tailor-made apolipoprotein A-I crown fulfills nanoparticles synergistically attacking tumor cells and M2 TAMs via binding with overexpressed scavenger receptors. The findings witness the targeted accumulation and potent cytotoxicity of the hybrid nanoparticles for M2 TAMs and tumor cells; especially, elimination of M2 TAMs in tumor microenvironment holds back Snail-enhancing transforming growth factor (TGF)-β signal pathway, which collaborates with Snail silencing in tumor cells to reverse epithelial mesenchymal transition (EMT) and metastasis-promoting niche. Collectively, the synergistic targeting therapeutic platform could provide a promising solution for metastatic tumor treatment.

Research Progress with Atractylone as an Antitumor Agent

Atractylone is a sesquiterpenoid compound extracted from Rhizoma Atractylodis. As one of the main active components in the volatile oil of the Atractylodes genus, it has exhibited certain therapeutic effects, including anti-inflammatory, antiviral, antioxidant, antiallergic, antiangiogenic, and neuroprotective activities, among others. With further research on the chemical constituents and pharmacology of sesquiterpenes, research on the antitumor activity of Atractylone has also been further expanded. Much of the current literature pays particular attention to the antitumor activity of Atractylone, which was found to inhibit the apoptosis of tumor cells and prevent growth, invasion, and migration through different apoptosis pathways and signaling pathways. Due to its promising potential for cancer prevention, it may play a role in reducing the incidence of malignant tumors. In this paper, the antitumor activity and mechanism of Atractylone are reviewed, providing a reference to inform future research on the tumor treatment, clinical application, and further development and utilization of this plant genus.

Size transformable organic nanotheranostic agents for NIR-II imaging-guided oncotherapy

Nanotheranostic agents combined the second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging with phototherapy strategy have attracted tremendous interest. However, the actual efficacy of NIR-II probes could be weakened by their limited accumulation and penetration in tumor tissues. Herein, a size-transformable NIR-II nanotheranostic agent (BBT-HASS@FPMPL NPs) is employed for simultaneously enhanced penetration and retention in deep tumor tissue to realize precise image and effective PTT therapy. BBT-HASS@FPMPL NPs were first formed by using hyaluronic acid (HA) chains and disulfide bonds as stimuli-responsive "lock" to efficiently load conjugated oligomer (BBTN+), and then folic acid (FA) modified polylysine (FPMPL) shell was stacked at the surface by electrostatic interaction. Dual targeting with HA and FA is expected to lead to more selective targeting and better accumulation of BBT-HASS@FPMPL NPs in tumor sites. Simultaneously, obvious particle size reduction and charge reversal can be triggered in acidic tumor microenvironment to achieve deep intratumor filtration through transcytosis. Following tumor penetration, size change was further initiated by overexpressed hyaluronidase and GSH in tumor. Free BBTN+ can be subsequently released from nanoparticles to promote specific intratumor retention, which synergistically enhance photothermal therapeutic efficacy. Owing to sufficient tumor accumulation and deep penetration, the NIR-II emission of BBTN+ could further be used for precise monitoring of subcutaneous tumor progression in mice for 6 days with just one dose injection. We expect that such nanotheranostic platform that combined the high resolution of NIR-II fluorescence with deep tumor penetration and long intratumor retention could be useful for real-time monitoring of tumor process, precise diagnosis, and enhanced phototherapy.

Bufalin-loaded vitamin E succinate-grafted chitosan oligosaccharide/RGD-conjugated TPGS mixed micelles inhibit intraperitoneal metastasis of ovarian cancer

Background

Intraperitoneal metastasis is one of the major causes of the high mortality rate of ovarian cancer. Bufalin (BU) is an effective component of the traditional Chinese medicine Chansu that exerts antitumor effects, including metastasis inhibition. In our previous studies, we found that BU inhibited the migration and invasion of ovarian cancer cells. However, the application of BU is limited due to its insolubility, toxicity and imprecise targeting. The aim of this study was to use vitamin E succinate (VES)-grafted chitosan oligosaccharide (CSO)/arginine-glycine-aspartic acid peptide (RGD)-conjugated d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) mixed micelles (VeC/T-RGD MMs) to deliver BU to ovarian cancer cells to inhibit intraperitoneal metastasis. Moreover, the toxicity of BU was reduced by coating it with the mixed micelles to increase its biocompatibility for practical applications.

Results

The BU-loaded VeC/T-RGD MMs (BU@MMs) had an average diameter of 161 ± 1.4 nm, a zeta potential of 4.49 ± 1.54 mV and a loading efficiency of 2.54%. The results showed that these micelles inhibited cell proliferation, induced apoptosis, and reduced the migration and invasion of A2780 and SKOV3 cells. Further studies indicated that BU@MMs enhanced the levels of e-cadherin and decreased the expression levels of N-cadherin, vimentin and Snail in vitro. In addition, the mixed micelles effectively enhanced the anticancer effect and inhibited intraperitoneal metastasis in intraperitoneal metastatic models. The BU@MMs exhibited fewer toxic side effects than BU, indicating better biocompatibility and biosafety for in vivo applications.

Conclusions

Our studies show that BU@MMs are a potential multifunctional nano-drug delivery system that can effectively inhibit the intraperitoneal metastasis of ovarian cancer.

Crucial role of hsa-mir-503, hsa-mir-1247, and their validation in prostate cancer

BACKGROUND

Prostate cancer (PC) is a common urinary system malignancy, and advanced PC patients had a poor prognosis due to recurrence or distant metastasis. Therefore, it's imperative to reveal more details in tumorigenesis and prognosis of PC patients.

METHODS

The miRNA and mRNA expression profile data of 485 PC patients were obtained from The Cancer Genome Atlas database. The univariate Cox regression was applied to screen miRNAs relating to prognosis of PC. Then miRTarBase was used to predict target mRNAs of miRNAs. The hsa-mir-503/hsa-mir-1247 knockdown in 22RV1 cells was established to evaluate the effect of these two miRNAs on tumor cell migration and invasion ability. Flow cytometry was used to detect the effect of hsa-mir-503/hsa-mir-1247 knockdown on 22RV1 apoptosis rate.

RESULTS

Univariate Cox regression analysis identified hsa-mir-503 as a poor and hsa-mir-1247 as a favorable prognostic marker. Totally 649 target mRNAs were screened, among which DUSP19, FGF2, and SLC2A5 had a negative correlation with hsa-mir-503, while FGF2 and VSTM4 had a positive correlation with hsa-mir-1247. In 22RV1 cells, hsa-mir-503 was up-regulated, and hsa-mir-1247 was down-regulated. hsa-mir-503 knockdown attenuated the migration and invasion of 22RV1 cells, while hsa-mir-1247 knockdown exhibited the opposite effect. In addition, hsa-mir-503 knockdown promoted 22RV1 cell apoptosis. hsa-mir-1247 overexpression significantly inhibited the tumor growth of PC in vivo.

CONCLUSIONS

Herein, we demonstrated that hsa-mir-503 and hsa-mir-1247 could serve as new prognostic markers of PC, and hsa-mir-1247 had great potential to inhibit PC progression by suppressing the migration and invasion ability in vitro and in vivo.

A dual drug-loaded peptide system with morphological transformation prolongs drug retention and inhibits breast cancer growth

The treatment of breast cancer relies heavily on chemotherapy, but chemotherapy is limited by the disadvantages of poor targeting, susceptibility to extracellular matrix (ECM) interference and a short duration of action in tumor cells. To address these limitations, we developed an amphipathic peptide containing an RGD motif, Pep1, that encapsulated paclitaxel (PTX) and losartan potassium (LP) to form the drug-loaded peptide PL/Pep1. PL/Pep1 self-assembled into spherical nanoparticles (NPs) under normal physiological conditions and transformed into aggregates containing short nanofibers at acidic pH. The RGD peptide facilitated tumor targeting and the aggregates prolonged drug retention in the tumor, which allowed more drug to reach and accumulate in the tumor tissue to promote apoptosis and remodel the tumor microenvironment. The results of in vitro and in vivo experiments confirmed the superiority of PL/Pep1 in terms of targeting, prolonged retention and facilitated penetration for antitumor therapy. In conclusion, amphipathic peptides as coloaded drug carriers are a new platform and strategy for breast cancer chemotherapy.

Tumor-overexpressed enzyme responsive amphiphiles small molecular self-assembly nano-prodrug for the chemo-phototherapy against non-small-cell lung cancer

Rational design of self-assembly drug amphiphiles can provide a promising strategy for constructing nano-prodrug with high drug loading, smart stimuli-responsive drug release and high tumor selectivity. Herein, we report a small molecular amphiphile prodrug that can self-assemble into multifunctional nano-prodrug for enhanced anticancer effect by the combination of chemotherapy and phototherapy (PDT/PTT). In this prodrug, the simple insertion of quinone propionate into hydrophilic drug Irinotecan (Ir) generates suitable amphiphiles that endow a good self-assembly behavior of the prodrug and transform it into a stable and uniform nanoparticle. Interestingly, this excellent self-assembly behavior can load phototherapy agent ICG to form a multifunctional nano-prodrug, thereby enhancing the chemotherapeutic effect with PDT/PTT. Importantly, the quinone propionic acid moiety in the prodrug showed a high sensitivity to the overexpressed NAD(P)H:quinone oxidoreductase-1 (NQO1) in non-small cell lung cancer (NSCLC) cells, and this sensitivity enables the disassembly of nano-prodrug and efficient NQO1-responsive drug release. To further enhance the drug accumulation on tumor tissue and migrate the blood clearance, a biomimetic nano-prodrug has been successfully explored by coating hybrid membrane on the above nano-prodrug, which displays high selective inhibition of tumor growth and metastasis on NSCLC mice model. Our findings provide new insights into the rational design of tumor-overexpressed enzyme responsive nano-prodrug for cancer combinational therapy.

Tumor microenvironment-activated multi-functional nanodrug with size-enlargement for enhanced cancer phototheranostics

Phototheranostics that integrate diagnosis and treatment modalities have shown great promise in personalized cancer therapy. However, the "always on" characteristics often lead to suboptimal imaging quality and severe side effects. Herein, we report the construction of a perylenemonoimide based nanodrug CPMI NP with multi-functional activatable theranostic capability. The nanodrug is facilely co-assembled from a prodrug CPMI and DSPE-mPEG2000. In a tumor microenvironment (TME) with excessive glutathione (GSH), CPMI undergoes a cascade reaction to generate the phototheranostic molecule NPMI and the chemodrug chlorambucil, simultaneously switching on the near-infrared (NIR) fluorescence, photothermal effect, and drug release. The photothermal conversion efficiency is as high as 52.2%. Moreover, NPMI exhibits an enhanced intermolecular π-π stacking effect, leading to significant size-enlargement of the nanodrug and prolonged tumor retention. Due to TME-activation, the strong in vivo fluorescence signal of the tumor can be observed 144 h post injection with a high signal-to-noise ratio of up to 17. The enhanced tumor inhibition efficiency of the nanodrug is confirmed through activatable chemo-photothermal therapy. This work paves the way for the design of activatable phototheranostic agents for accurate cancer diagnosis and treatment.

Drug conjugate-based anticancer therapy - Current status and perspectives

Drug conjugates are conjugates comprising a tumor-homing carrier tethered to a cytotoxic agent via a linker that are designed to deliver an ultra-toxic payload directly to the target cancer cells. This strategy has been successfully used to increase the therapeutic efficacy of cytotoxic agents and reduce their toxic side effects. Drug conjugates are being developed worldwide, with the potential to revolutionize current cancer treatment strategies. Antibody-drug conjugates (ADCs) have developed rapidly, and 14 of them have received market approval since the first approval event by the Food and Drug Administration in 2000. However, there are some limitations in the use of antibodies as carriers. Other classes of drug conjugates are emerging, such as targeted drugs conjugated with peptides (peptide-drug conjugates, PDCs) and polymers (polymer-drug conjugates, PolyDCs) with the remaining constructs similar to those of ADCs. These novel drug conjugates are gaining attention because they overcome the limitations of ADCs. This review summarizes the current state and advancements in knowledge regarding the design, constructs, and clinical efficacy of different drug conjugates.

Recent trends of bioconjugated nanomedicines through nose-to-brain delivery for neurological disorders

The global burden of neurological disorders has been increasing day by day which calls for immediate attention to the solutions. Novel drug delivery systems are one of the alternatives that we count on to counteract these disorders. As the blood-brain barrier creates a significant hindrance to the delivery of drugs across the endothelium lining of the brain, nose-to-brain delivery has been the favorite option to administer such drugs. In recent times, bioconjugation has been viewed as a rapidly growing area in the field of pharmaceuticals. The pharmaceutical industry and academic research are investing significantly in bioconjugated structures as an attractive and advantageous potential aid to nanoparticulate delivery systems, with all of its flexible benefits in terms of tailor grafting and custom design as well as overcoming the majority of their drawbacks. This review discusses drug delivery via the intranasal route and gives insight into bioconjugation systems for drug molecules, their chemistry, and benefits over other systems. Conjugation of drugs/macromolecules with peptides, carbohydrates, ligands, and nucleic acids has also been discussed in detail. The figure represents few types of novel drug delivery systems and molecules that have been attempted by researchers for nose-to-brain delivery through nasal (mucosal) route for the effective management of epilepsy, Alzheimer's disease, brain cancer, and other brain disorders.

Engineering Single-Atom Iron Nanozymes with Radiation-Enhanced Self-Cascade Catalysis and Self-Supplied H2O2 for Radio-enzymatic Therapy

Single-atom nanozymes (SAzymes), with individually isolated metal atom as active sites, have shown tremendous potential as enzyme-based drugs for enzymatic therapy. However, using SAzymes in tumor theranostics remains challenging because of deficient enzymatic activity and insufficient endogenous H₂O₂. We develop an external-field-enhanced catalysis by an atom-level engineered FeN₄-centered nanozyme (FeN₄-SAzyme) for radio-enzymatic therapy. This FeN₄-SAzyme exhibits peroxidase-like activity capable of catalyzing H₂O₂ into hydroxyl radicals and converting single-site Fe^II species to Fe^III for subsequent glutathione oxidase-like activity. Density functional theory calculations are used to rationalize the origin of the single-site self-cascade enzymatic activity. Importantly, using X-rays can improve the overall single-site cascade enzymatic reaction process via promoting the conversion frequency of Fe^II/Fe^III. As a H₂O₂ producer, natural glucose oxidase is further decorated onto the surface of FeN₄-SAzyme to yield the final construct GOD@FeN₄-SAzyme. The resulting GOD@FeN₄-SAzyme not only supplies in situ H₂O₂ to continuously produce highly toxic hydroxyl radicals but also induces the localized deposition of radiation dose, subsequently inducing intensive apoptosis and ferroptosis in vitro. Such a synergistic effect of radiotherapy and self-cascade enzymatic therapy allows for improved tumor growth inhibition with minimal side effects in vivo. Collectively, this work demonstrates the introduction of external fields to enhance enzyme-like performance of nanozymes without changing their properties and highlights a robust therapeutic capable of self-supplying H₂O₂ and amplifying self-cascade reactions to address the limitations of enzymatic treatment.

Self-assembled peptide-paclitaxel nanoparticles for enhancing therapeutic efficacy in colorectal cancer

Chemotherapy is one of the main treatments for colorectal cancer, but systemic toxicity severely limits its clinical use. Packaging hydrophobic chemotherapeutic drugs in targeted nanoparticles greatly improve their efficacy and reduce side effects. We previously identified a novel colorectal cancer specific binding peptide P-LPK (LPKTVSSDMSLN) from phage display peptide library. Here we designed a self-assembled paclitaxel (PTX)-loaded nanoparticle (LPK-PTX NPs). LPK-PTX NPs displayed a superior intracellular internalization and improved tumor cytotoxicity in vitro. Cy5.5-labeled LPK-PTX NPs showed much higher tumor accumulation in colorectal cancer-bearing mice. Furthermore, LPK-PTX NPs exhibit enhanced antitumor activity and decreased systemic toxicity in colorectal cancer patient-derived xenografts (PDX) model. The excellent in vitro and in vivo antitumor efficacy proves the improved targeting drug delivery, suggesting that peptide P-LPK has potential to provide a novel approach for enhanced drug delivery with negligible systemic toxicity.

Targeted intelligent mesoporous polydopamine nanosystems for multimodal synergistic tumor treatment

Developing intelligent responsive platforms to carry out high-performance therapy is of great interest for the treatment of tumors and their metastases. However, effective drug loading, activity maintenance, off-target leakage, and response to collaborative therapy remain great challenges. Herein, a targeted intelligent responsive mesoporous polydopamine (MPDA) nanosystem was reported for use in gene-mediated photochemotherapy for synergistic tumor treatment. First, the MPDA was surface modified to maintain a positive charge near the surface and to impart active targeting. Then, gambogic acid (GA) was encapsulated in the MPDA, solidified by phase change materials (PCMs), and finally loaded with siRNA by electrostatic interactions to obtain the smart nanodelivery system (PPMD@GA/si). In vitro and in vivo experiments showed that it not only effectively avoids siRNA inactivation and accidental release of GA, but also possesses potential for targeted accumulation to tumor tissue and mild-temperature photothermal therapy and chemotherapy via near infrared (NIR) radiation. Additionally, the release of siRNA could also effectively inhibit tumor invasion and metastasis to realize multimodal synergistic therapy. Overall, our studies provide a promising idea for synergistic tumor and metastasis treatment based on vector construction.

Co-delivery of proanthocyanidin and mitoxantrone induce synergistic immunogenic cell death to potentiate cancer immunotherapy

Immunological checkpoint inhibitors provide a revolutionary method for cancer treatment. However, due to low tumor mutations and insufficient infiltration of immune cells in the tumor microenvironment, 85% of colorectal cancer...

Supramolecular peptide nano-assemblies for cancer diagnosis and therapy: from molecular design to material synthesis and function-specific applications

Peptide molecule has high bioactivity, good biocompatibility, and excellent biodegradability. In addition, it has adjustable amino acid structure and sequence, which can be flexible designed and tailored to form supramolecular nano-assemblies with specific biomimicking, recognition, and targeting properties via molecular self-assembly. These unique properties of peptide nano-assemblies made it possible for utilizing them for biomedical and tissue engineering applications. In this review, we summarize recent progress on the motif design, self-assembly synthesis, and functional tailoring of peptide nano-assemblies for both cancer diagnosis and therapy. For this aim, firstly we demonstrate the methodologies on the synthesis of various functional pure and hybrid peptide nano-assemblies, by which the structural and functional tailoring of peptide nano-assemblies are introduced and discussed in detail. Secondly, we present the applications of peptide nano-assemblies for cancer diagnosis applications, including optical and magnetic imaging as well as biosensing of cancer cells. Thirdly, the design of peptide nano-assemblies for enzyme-mediated killing, chemo-therapy, photothermal therapy, and multi-therapy of cancer cells are introduced. Finally, the challenges and perspectives in this promising topic are discussed. This work will be useful for readers to understand the methodologies on peptide design and functional tailoring for highly effective, specific, and targeted diagnosis and therapy of cancers, and at the same time it will promote the development of cancer diagnosis and therapy by linking those knowledges in biological science, nanotechnology, biomedicine, tissue engineering, and analytical science.

Redox-sensitive hyaluronic acid-cholesterol nanovehicles potentiate efficient transmembrane internalization and controlled release for penetrated "full-line" inhibition of pre-metastatic initiation

Metastatic breast cancer is a major cause of cancer-related mortality worldwide. The tumor-specific penetration and triggered drug release for "full-line" inhibition of pre-metastatic initiation are of essential importance in improving mortality rates. Here, a crosslinked, redox-sensitive amphiphilic conjugate (cHLC) was constructed with a combination of features, including hyaluronic acid (HA)-mediated tumor active targeting, lipoic acid (LA) core-crosslinking based bio-stability and reducibility, and lipid raft anchoring-promoted HA-mediated endocytosis through cholesterol (CHO) modification for the penetrated co-delivery of paclitaxel (PTX) and the multi-targeted anti-metastatic agent, silibinin (SB). Resultantly, the nanodrug (cHLC/(PTX + SB)) demonstrated enhanced tumor cytoplasm-selective rapid drug delivery in a 4T1 model both in vitro and in vivo. The released SB efficiently sensitized cells to PTX treatment and inhibited the whole process of pre-metastatic initiation including epithelial-to-mesenchymal transition (EMT), local and blood vessel invasion. The exquisite design of this delivery system provides a deep insight into enhancing focus accessibility of multi-targeted drugs for an efficient inhibition of tumor metastasis.

Application and Future Prospect of Extracellular Matrix Targeted Nanomaterials in Tumor Theranostics

Systemic chemotherapy and radiotherapy have been widely used in clinics for several decades, but their disadvantages, such as systemic cytotoxicity and severe side effects, are the biggest obstacle to maximum therapeutic efficacy. In recent years, the impact of extracellular matrix components in tumor progression has gained the attention of researchers, and with the rapid development of nanomaterials, extracellular matrix targeted nanomaterials have become a promising strategy in tumor theranostics. In this review, we will outline the recent and relevant examples of various tumor extracellular matrix targeted nanomaterials applied in tumor therapy and imaging. And we will discuss the challenges and prospects of nanomaterials for future tumor therapy.

Peptide-Chitosan Engineered Scaffolds for Biomedical Applications

Peptides are signaling epitopes that control many vital biological events. Increased specificity, synthetic feasibility with concomitant lack of toxicity, and immunogenicity make this emerging class of biomolecules suitable for different applications including therapeutics, diagnostics, and biomedical engineering. Further, chitosan, a naturally occurring linear polymer composed of d-glucosamine and N-acetyl-d-glucosamine units, possesses anti-microbial, muco-adhesive, and hemostatic properties along with excellent biocompatibility. As a result, chitosan finds application in drug/gene delivery, tissue engineering, and bioimaging. Despite these applications, chitosan demonstrates limited cell adhesion and lacks biosignaling. Therefore, peptide-chitosan hybrids have emerged as a new class of biomaterial with improved biosignaling properties and cell adhesion properties. As a result, recent studies encompass increased application of peptide-chitosan hybrids as composites or conjugates in drug delivery, cell therapy, and tissue engineering and as anti-microbial material. This review discusses the recent investigations involving chitosan-peptide materials and uncovers various aspects of these interesting hybrid materials for biomedical applications.

Advancement of nanoscience in development of conjugated drugs for enhanced disease prevention

Nanoscience and nanotechnology is a recently emerging and rapid developing field of science and has also been explored in the fields of Biotechnology and Medicine. Nanoparticles are being used as tools for diagnostic purposes and as a medium for the delivery of therapeutic agents to the specific targeted sites under controlled conditions. The physicochemical properties of these nanoparticles give them the ability to treat various chronic human diseases by site specific drug delivery and to use in diagnosis, biosensing and bioimaging devices, and implants. According to the type of materials used nanoparticles can be classified as organic (micelles, liposomes, nanogels and dendrimers) and inorganic (including gold nanoparticles (GNPs), super-paramagnetic iron oxide nanomaterials (SPIONs), quantum dots (QDs), and paramagnetic lanthanide ions). Different types of nanoparticle are being used in conjugation with various types of biomoities (such as peptide, lipids, antibodies, nucleotides, plasmids, ligands and polysaccharides) to form nanoparticle-drug conjugates which has enhanced capacity of drug delivery at targeted sites and hence improved disease treatment and diagnosis. In this study, the summary of various types of nanoparticle-drug conjugates that are being used along with their mechanism and applications are included. In addition, the various nanoparticle-drug conjugates which are being used and which are under clinical studies along with their future opportunities and challenges are also discussed in this review.