Magnetic resonance imaging-guided and targeted theranostics of colorectal cancer

Colorectal cancer(CRC)is the most common gastrointestinal tract cancer worldwide and is associated with high morbidity and mortality.The development of nanosized drug delivery systems has provided a new direction in CRC treatment.Among these systems,magnetic nanoparticle(MNP)-based multifunctional platforms provide a novel strategy for magnetic resonance imaging(MRI)-related cancer theranostics.At the beginning o f this original review,the carcinogenesis and treatment status o f CRC are summarized.Then,diversified preparation and functionalization methods of MNPs are systematically analyzed,followed by MRIinvolved theranostic strategies.The latest progress in MRI-mediated multimode diagnosis and image-guided targeted therapy in CRC management is the main focus.Finally,the major challenges in promoting MRI-induced precise theranostics of CRC in clinical practice are discussed.

Biomaterial-assisted photoimmunotherapy for synergistic suppression of cancer progression

Photoimmunotherapy is an emerging treatment modality that uses photothermal,photodynamic and photochemical processes to fight against cancer by eliciting a robust host immune response.Recently,various nanoformulations of biomaterials have been rationally designed as highly effective photosensitive agents,immunoadjuvants or carriers to enhance phototherapeutic efficacy,boost immune stimulation,amplify nano-permeability and monitor cancer progression in situ.Nevertheless,relying solely on a single-modality therapy may not completely ablate primary tumors,and the metastasis and recurrence of tumors remain a serious challenge.To solve this issue,the strategy of combining photoimmunotherapy with other immunotherapies,such as immune checkpoint blockade,chimeric antigen receptor-T cell or cytokine therapy,can greatly enhance the effectiveness of oncology treatment and reduce the traditional adverse effects.Thus,it is very valuable to summarize the research progress in biomaterial-assisted combination photoimmunotherapy for clinical translation.In this review,the recent advances in constructing multifunctional nano-biomaterials for combinatorial photoimmunotherapy of cancer are summarized.Furthermore,the opportunities,challenges,future trends and prospects in this field are also analyzed to pave the way for advancing the next generation of clinical cancer management strategies.

Bone analysis using an aggregation-induced emission-active iridium complex

Fluorescent analysis of bone provides valuable insights into bone structures.However,conventional dyes suffer from low specificity on bone tissue,small stokes shift,short fluorescent lifetime,and aggregation-caused quenching effect,which result in low efficacy and artifacts.In this work,we design an aggregation-induced emission(AIE)-active iridium(III)complex(Ir-BP2)as a highly selective,convenient,nondestructiveness,and dual-mode staining agent for bone analysis.Ir-BP2 containing phosphonate groups selectively binds to hydroxyapatites,the main component of bone matrix,and exhibits turn-on AIE phosphorescence with prolonged lifetime.Ir-BP2 exhibits promising biosafety and offers higher accuracy in staining calcium deposits than conventional Alizarin Red S staining assay when it is employed in real-time monitoring of osteogenesis differentiation process.A ready-to-use staining spray of Ir-BP2 is fabricated.By using fluorescent imaging and lifetime imaging,Ir-BP2 staining provides valuable insights into bone microstructure analysis,microdamage diagnosis,and bone growth state identification.Further,Ir-BP2 is successfully applied on a human spine vertebra for diagnosing bone invasiveness of eosinophilic granuloma,validating its clinical practice.This work presents a powerful tool in bone analysis and will lead to new approaches for the diagnosis and treatment of bone-related diseases.

Cathepsin B-responsive nanodrug delivery systems for precise diagnosis and targeted therapy of malignant tumors

The tumor microenvironment(TME)significantly influences cancer evolution and therapeutic efficacy.Targeting biofunctional molecules to the TME has long been appreciated as a means of raising local drug concentrations and reducing systemic toxicities.The booming nanotechnology field has realized the importance of cathepsin B to derive a variety of intelligent enzyme-responsive nanosized drug delivery systems(nanoDDS)to improve treatment responses and clinical outcomes.In this tutorial review,after introducing the molecular structure and physiological/pathological functions of cathepsin B,the outstanding achievements of cathepsin B-responsive nanoplatforms in the precise diagnosis,targeted therapy,and synergistic theranostics of malignant tumors are systematically described.Finally,the challenges of enzyme-substrate incompatibility,low diagnostic sensitivity,mass production and biocompatibility of multifunctional nanoDDS are considered in order to successfully promote them to clinical applications.

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

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

Allele-defined genome reveals biallelic differentiation during cassava evolution

Dear Editor,Generation of heterozygous genomes by hybridization between or within species can help maintain plant diversity and serve as a potential source of new species(Baek et al.,2018).Moreover,genomic heterozygosity is associated with genomic coadaptation,developmental stability,and heterosis.Accurate definition of alleles in haplotypes is necessary to precisely characterize allelic variation controlling agriculturally important traits(Shi et al.,2019).Currently,most released genomes have mosaic assembly of haplotypes due to random selection or collapse of alleles during genome assembly(Shi et al.,2019),which masked allelic variation and functional differentiation of divergent alleles in heterozygous species.