Bioconjugate Chemistry最新文献

Conjugation of ligands to oligonucleotides is a prominent strategy to enhance (bio)properties of nucleic acids such as cellular uptake/delivery, bioavailability, detection/tracking, and more. Here, we report a simple, cost-effective, and streamlined methodology for the incorporation of various conjugation handles into DNA and RNA. Pyrimidine nucleosides are linked to the solid support via a disulfide-containing linker covalently attached through the nucleobase, removing the typical sugar point-of-attachment requirement. We showcase a conjugation strategy in which nucleic acid strands can be permanently tagged with a ligand (via an azido group) and reversibly conjugated to another (via the linker containing a disulfide and primary amino group). Freed thiols can undergo further conjugation in certain constructs. Ultimately, our conjugation handles containing various orthogonal functional groups (e.g., azido, amino, and disulfide functional groups) will find applications in biotechnology and chemical biology.

We developed a dual-modal GSTP probe that exhibits GST-responsive fluorescence enhancement and photoacoustic signal reduction. GSTP demonstrated excellent selectivity, sensitivity, and biocompatibility. In diabetic mice, GSTP revealed a decreased level of hepatic GST activity partially restored by metformin treatment, supported by serum analysis and histopathological evaluation, highlighting its clinical translation potential for diabetes monitoring.

High-efficiency molecular recognition tools, such as aptamers and antibodies, play a pivotal role in precise cancer theranostics. However, their noncovalent interactions with target molecules often limit their accumulation and retention within the tumor microenvironment. In this study, we introduce a class of membrane protein-targeting and membrane-inserting (MBI) chimeras, created by conjugating a membrane protein-targeting aptamer (as a model) with a pH-responsive membrane-inserting domain derived from the pH-Low Insertion Peptide (pHLIP). By harnessing the synergistic effects of these two distinct mechanisms, these MBI chimeras efficiently bind to tumor cells in the acidic microenvironment, enabling efficient delivery of chlorin e6 (Ce6) to the targeted cells. In vivo studies demonstrate that the Ce6-load MBI chimera, Sgc8-pHLIP, exhibits significantly enhanced photodynamic therapeutic efficacy compared to Ce6-loaded control constructs, which lack either membrane insertion functionality or specific membrane protein recognition. Overall, this work presents a promising strategy for the development of highly efficient molecular recognition tools for precise cancer therapeutics.

Hydrogen sulfide (H₂S), once regarded solely as a toxic gas, has emerged as a star molecule for potential anticancer therapy. However, precise spatiotemporal control of H₂S delivery remains challenging due to rapid diffusion and systemic toxicity risks. Recent advances in nanotechnology have enabled the design of H₂S-generating nanomedicines (HSGNs) that address these limitations through stimuli-responsive in situ H₂S generation. Through engineered design, HSGNs with different in situ generation mechanisms (such as pH and GSH responses) can be designed to improve the controlled release of H₂S within cells effectively, and considerable efforts have been made to explore their multimodal synergistic effects in cancer therapy. This review systematically examines the development of HSGNs, focusing on material innovations, controlled-release strategies, and multimodal therapeutic applications in cancer treatment, and, finally, provides a prospective view of the future development of HSGNs to accelerate their practical clinical translation and application.

Drug combination is a cornerstone of modern medicine, particularly in oncology. However, drug combinations often fail due to poor disease site tropism and additive toxicities of composite drugs. Among targeted drug delivery systems for reducing toxicity, the antibody-drug conjugate (ADC) is effective for single cytotoxic payload delivery. Multipayload ADC for combination therapy is mostly limited to two chemotherapeutics at fixed ratios, hampered by a lack of payload combination synergy/toxicity knowledge and complex antibody engineering and linker chemistries. Here we design synergistic payload-antibody ratiometric conjugate (SPARC) based on an elucidation of payload ratio-dependent pharmacology and toxicology of drug combinations delivered by a previously described clinical-stage T1000-ADC linker. Multi-T1000 payload (MTP) moieties are synthesized through a convergent process by orthogonally linking two or more azide–alkyne-modified, clickable T1000 payloads. Direct conjugation of an MTP to a native antibody or combinatorial, sequential conjugation of two MTPs to engineered and native cysteines of THIOMABs leads to a programmable assembly of SPARCs with 2–6 payloads, a total drug antibody ratio (DAR) as high as 30, and a tunable payload ratio from 1 to 10. SPARCs are stable and homogeneous, and conjugation of multiple payloads does not affect antibody binding. SPARCs achieve a more precise pharmacological discrimination in vivo, with lower off-target additive toxicity due to reduced payload release compared to single-payload ADCs but higher efficacy in targeted cells by synergistic/additive interactions among pharmacokinetically synchronized payloads. SPARCs combining Topoisomerase I (TOP1) with DNA Damage Response (DDR) inhibitors outperform single-TOP1 ADCs and free-drug combinations. SPARCs also exhibit improved safety profiles with reduced hematological toxicity and synchronized payload pharmacokinetics. SPARC has the potential to usher in a new generation of ADCs by reusing abandoned drugs as deliverable payloads and represents a transformative approach to precision combination therapy, addressing unmet needs in oncology and other disease areas through programmable, rationally designed drug codelivery.

For siRNA-based therapeutics that require repeated administration, the accumulation of ionizable lipids in the body could cause in vivo safety issues. In the present study, we examined the feasibility of a bile acid–histidine decapeptide (H10) conjugate as a novel, biocompatible, and potential additive to reduce the proportion of ionizable lipids for the formulation of LNPs. A lithocholic acid (LCA)-H10 conjugate (LH conjugate) was synthesized and incorporated into the LNPs with low proportions of ionizable lipids (LiLNPs). The fabricated LH conjugate-containing LiLNPs (LiLNP-LH) exhibited more promising gene silencing activity than LiLNPs, despite their similar particle size and morphology. Additionally, LiLNP-LHs exhibited an elevated liver accumulation after intravenous injection and significantly decreased release of the inflammatory cytokines, compared with conventional LNPs with high proportions of ionizable lipids (HiLNPs). Thus, we successfully reduced the proportion of ionizable lipids in LNPs by adding LH conjugates, which could serve as carriers for diverse siRNA therapeutics with promising silencing activity and superior in vivo safety.

Thiol-functionalized conjugated polymers offer a versatile platform for designing fluorescent nanomaterials with biomedical relevance. In this study, a thiol modified conjugated polymer composed of benzoxadiazole (BO) and carbazole (POxC-SH) was synthesized, then converted into fluorescent nanoparticles (POxC-SH NPs) via a reprecipitation method. The nanoparticles exhibited strong photoluminescence, colloidal stability, and monodispersity in media. Surface thiol groups enabled conjugation with peptide and protein components isolated from the pleural fluid of lung adenocarcinoma patients using SMCC cross-linking. The resulting bioconjugated nanoprobe was characterized by spectroscopic methods, FTIR, XPS, and Mass spectrometry. Cellular studies in A549 and BEAS-2B cell lines demonstrated efficient internalization and low toxicity of both native and conjugated nanoparticles. This work presents a proof of concept for using thiol-modified conjugated polymer nanoparticles as intrinsically fluorescent, patient-adaptable imaging agents, bridging conjugated polymer chemistry with targeted biomedical applications.

Periodontitis is a chronic inflammatory oral disease characterized by dysregulated host immune responses. Modulating the immune microenvironment has emerged as a promising therapeutic strategy to address the limitations of conventional treatments. To explore this approach, we developed uniformly sized dopamine-derived carbon dots (DACDs) with smooth surfaces via hydrothermal synthesis using dopamine as the precursor. The synthesized DACDs exhibited favorable biosafety and considerable photothermal conversion capability. In vitro experiments employing quantitative real-time PCR (qRT-PCR), Western blotting, and immunofluorescence staining demonstrated that DACDs synergized with mild photothermal therapy (MPTT) to significantly downregulate pro-inflammatory cytokine expression in RAW264.7 cells. In vivo studies further confirmed that the combined application of DACDs and MPTT markedly reduced periodontal inflammation and attenuated alveolar bone resorption, as evidenced by Micro-CT analysis and histological staining. Collectively, DACDs mitigate bone destruction by suppressing inflammatory cascades, establishing a novel and effective immunomodulatory strategy for the management of periodontitis.

KS-487 is a cyclic peptide previously reported to bind low-density lipoprotein receptor-related protein 1 (LRP1) and exhibit blood–brain barrier (BBB) permeability. In this study, we evaluated the in vivo BBB permeability and selectivity of KS-487 in comparison with those of Angiopep-2 (ANG2), a widely used linear LRP1-binding peptide. Indocyanine green (ICG)-labeled KS-487 and ANG2 were subcutaneously administered to mice, and their biodistribution was assessed at 24, 48, and 72 h by using in vivo imaging. ICG-KS-487 and ICG-ANG2 displayed comparable brain permeability and nearly identical time-course profiles. Notably, ICG-KS-487 demonstrated greater brain selectivity, defined as the ratio of brain to liver accumulation at 72 h. No adverse effects, including weight loss or histopathological abnormalities in major organs, were observed in mice treated with ICG-KS-487. These findings highlight the remarkable brain-targeting properties and safety profile of KS-487, supporting its potential utility as a targeting ligand for drug delivery to treat brain-related disorders.

Lipid nanoparticle (LNP) delivery of mRNA to specific cell types is a necessary task for the development of safe and effective medicines. LNP delivery to the liver is largely driven by the binding of serum ApoE to the LNP surface, followed by subsequent uptake in LDL receptor (LDL-R)-expressing hepatocytes, thereby reducing their utility in nonhepatocyte liver diseases. Herein, we developed an active targeting strategy to overcome this limitation by incorporating mannose-conjugated cholesterol into LNPs. Since cholesterol comprises about half of all molecules in LNPs, we reasoned that it could serve as a scaffold for active targeting. Mannosylated LNPs enhance uptake into liver sinusoidal endothelial cells (LSECs) and Kupffer cells over hepatocytes following intravenous administration in mice. This process correlated with the expression of mannose receptors (CD206) in LSECs and Kupffer cells, where significantly greater LNP uptake and functional mRNA delivery occurred in CD206⁺ cells. Higher activity and selectivity could be endowed by reducing the hydrophobic acyl chain length in poly(ethylene glycol) (PEG) lipids to induce faster PEG shedding in systemic circulation and increase LNP surface-accessible mannose, thereby increasing binding interactions with mannose receptors on CD206⁺ cells and subsequent LNP uptake. The results establish that cholesterol can be employed as a ligand carrier in LNPs for enriching mRNA delivery to specific cells in vivo. We anticipate that this general strategy of cholesterol modification can be extended to other ligands and cell types in the future.