Dual-Action Protein-siRNA Conjugates for Targeted Disruption of CD47-Signal Regulatory Protein α Axis in Cancer Therapy.

A series of successes in RNA interference (RNAi) therapies for liver diseases using lipid nanoparticles and N-acetylgalactosamine have heralded a current era of RNA therapeutics. However, alternative delivery strategies are required to take RNAi out of the comfort zone of hepatocytes. Here we report SIRPα IgV/anti-CD47 siRNA (vS-siCD47) conjugates that selectively and persistently disrupt the antiphagocytic CD47/SIRPα axis in solid tumors. Conjugation of the SIRPα IgV domain protein to siRNAs enables tumor dash through CD47-mediated erythrocyte piggyback, primarily blocking the physical interaction between CD47 on cancer cells and SIRPα on phagocytes. After internalization of the vS-siCD47 conjugates within cancer cells, the detached free-standing anti-CD47 siRNAs subsequently attack CD47 through the RNAi mechanism. The dual-action approach of the vS-siCD47 conjugate effectively overcomes the "don't eat me" barrier and stimulates phagocyte-mediated tumor destruction, demonstrating a highly selective and potent CD47-blocking immunotherapy. This delivery strategy, employing IgV domain protein-siRNA conjugates with a dual mode of target suppression, holds promise for expanding RNAi applications beyond hepatocytes and advancing RNAi-based cancer immunotherapies for solid tumors.

Discharge transition experienced by older Korean women after hip fracture surgery: a qualitative study.

BACKGROUND: This study aimed to explore older Korean women's discharge transition experiences after hip fracture surgery. METHODS: This was a descriptive qualitative study. Face-to-face interviews following hip fracture surgery were conducted on 12 women aged 65-87 years. Data were collected 1 to 2 days before discharge and again 4 weeks after discharge following hip fracture surgery, and were analyzed using qualitative content analysis. RESULTS: Four main themes were identified: (1) challenge of discharge transition: unprepared discharge, transfer into other care settings, and eagerness for recovery; (2) physical and psychological distress against recovery: frail physical state and psychological difficulties; (3) dependent compliance: absolute trust in healthcare providers, indispensable support from the family, and passive participation in care; and (4) walking for things they took for granted: hope of walking and poor walking ability. CONCLUSIONS: After their hip fracture surgeries, older women hoped to be able to walk and perform simple daily chores they previously took for granted. Considering the physical and psychological frailty of older women undergoing hip surgery, systematic nursing interventions including collaboration and coordination with other healthcare professionals and settings are necessary to ensure the quality of continuous care during their post-surgery discharge transition. Encouraging partial weight bearing and initiating intervention to reduce fear of falling at the earliest possible time are essential to attain a stable discharge transition. Additionally, older women should be invited to participate in their care, and family involvement should be encouraged during the discharge transition period in South Korea.

Versatile activatable vSIRPα-probe for cancer-targeted imaging and macrophage-mediated phagocytosis of cancer cells.

Signal-regulatory protein alpha (SIRPα) engaged by CD47, that is overexpressed in a wide range of human solid tumors, serves as a 'Don't eat me' signal for phagocytic cells such as macrophages and dendritic cells. The SIRPα-CD47 interactions have recently attracted increasing attention in both cancer diagnosis and cancer immunotherapy. Herein, we designed and suggested a lysosomal enzyme-activatable vSIRPα-probe (vSIRPα-probe) capable of facilitating CD47-targeted cancer imaging and eliciting anti-cancer immune responses depending on phagocytosis as a versatile platform for potential cancer theranostic applications. For more efficient and precise cancer targeting, a recombinant SIRPα variant (vSIRPα) having a 50,000-fold higher binding affinity to CD47 than wild-type SIRPα was used to fabricate the vSIRPα-probe by conjugating to a dark-quenched fluorogenic peptide that is a substrate of lysosomal endopeptidases. The vSIRPα-probe could specifically bind to CD47 in different types of cancer cells and be activated by dequenching after cellular internalization. By interrupting the SIRPα-CD47 interaction between macrophages and cancer cells, the vSIRPα-probe promoted the destruction of cancer cells by macrophage-mediated phagocytosis, which was highly comparable to the un-modified vSIRPα recombinant protein. In the mouse tumor-xenografts treated with intravenous injection of the vSIRPα-probe, its enhanced in vivo tumor-targeting and imaging abilities drastically diminished after blocking the SIRPα-CD47 interaction via intratumoral administration of anti-CD47 antibodies. This study demonstrates that our vSIRPα-probe provides a promising tumor-targeted immunotheranostic probe for a novel cancer diagnostic and therapeutic strategy.

Non-invasive in vivo imaging of caspase-1 activation enables rapid and spatiotemporal detection of acute and chronic inflammatory disorders.

Inflammasome plays a critical role in diverse inflammatory disorders, including cancers and Alzheimer's disease. It is induced by various pathogenic insults and activates caspase-1, a hallmark executor of inflammasome. Here, we developed an activatable fluorescence probe for visualization of active caspase-1. This caspase-1 probe is biocompatible, efficiently delivered into cells and tissues, and specifically emits fluorescence upon caspase-1 activation as assessed in in vitro and in vivo models of inflammatory conditions. We demonstrated efficient in vivo imaging of caspase-1 activation in early stages of various inflammatory conditions of mice models, including endotoxin shock, inflammatory bowel disorder, transplanted cancer, and Alzheimer's disease. Notably, the caspase-1 probe enables detection of neuroinflammation in vivo two months earlier than cognitive impairments occur in Alzheimer's disease model. We detected significant fluorescence emitted from inflamed sites, as well as their draining lymph nodes, by macroscopic imaging analysis within 30 min after systemic injection of the probe. This novel synthetic probe could be applied for efficient and rapid detection of caspase-1 activity in a spatiotemporal way by non-invasive imaging.

Visible light-induced apoptosis activatable nanoparticles of photosensitizer-DEVD-anticancer drug conjugate for targeted cancer therapy.

The therapeutic efficacy of photodynamic therapy (PDT) in cancer treatment is attributed to the conversion of tumor oxygen into reactive singlet oxygen (1O2) using photosensitizers. However, poor tissue penetration and rapid oxygen depletion have limited the effectiveness of PDT. Therefore, we have developed visible light-induced apoptosis activatable nanoparticles of the photosensitizer (Ce6)-caspase 3 cleavable peptide (Asp-Glu-Val-Asp, DEVD)-anticancer drug monomethyl auristatin E (MMAE) conjugate, resulting in Ce6-DEVD-MMAE nanoparticles. The average size of self-assembled Ce6-DEVD-MMAE nanoparticles was 90.8 ±â€¯18.9 nm. Compared with conventional PDT based on high-energy irradiation, the new therapy uses lower-energy irradiation to induce apoptosis of cancer cells, and activation of caspase 3 to successfully cleave the anticancer drug MMAE from the Ce6-DEVD-MMAE nanoparticles, resulting in strong cytotoxic effects in cancer cells. Notably, the one-time activation of MMAE in the Ce6-DEVD-MMAE nanoparticles further amplified the cytotoxic effect resulting in additional cell death in the absence of visible light irradiation. Furthermore, Ce6-DEVD-MMAE nanoparticles passively accumulated in the targeted tumor tissues via enhanced permeation and retention (EPR) effect in mice with squamous cell carcinoma (SCC7). The high levels of toxicity were retained after exposure to lower-energy irradiation. However, Ce6-DEVD-MMAE nanoparticles did not show any toxicity in the absence of exposure to visible light irradiation, in contrast to the toxicity of free MMAE (1-10 nM). Thus, the light-induced therapeutic strategy based on apoptotic activation of Ce6-DEVD-MMAE nanoparticles can be used to treat solid tumors inaccessible to conventional PDT.

Immunomodulatory nanodiamond aggregate-based platform for the treatment of rheumatoid arthritis.

We previously demonstrated that octadecylamine-functionalized nanodiamond (ND-ODA) and dexamethasone (Dex)-adsorbed ND-ODA (ND-ODA-Dex) promoted anti-inflammatory and pro-regenerative behavior in human macrophages in vitro. In this study, we performed a pilot study to investigate if these immunomodulatory effects translate when used as a treatment for rheumatoid arthritis in mice. Following local injection in limbs of mice with collagen type II-induced arthritis, microcomputed tomography showed that mice treated with a low dose of ND-ODA and ND-ODA-Dex did not experience bone loss to the levels observed in non-treated arthritic controls. A low dose of ND-ODA and ND-ODA-Dex also reduced macrophage infiltration and expression of pro-inflammatory mediators iNOS and tumor necrosis factor-α compared to the arthritic control, while a high dose of ND-ODA increased expression of these markers. Overall, these results suggest that ND-ODA may be useful as an inherently immunomodulatory platform, and support the need for an in-depth study, especially with respect to the effects of dose.

Advances in the strategies for designing receptor-targeted molecular imaging probes for cancer research.

Receptor targeted imaging has emerged as a promising tools for imaging tumor tissues. Receptor targeted molecular imaging confers critical information on clinicians including tumor location, expression level of certain receptors, and biological process, which enables early diagnosis and treatment of tumor to control cancer mortality. Receptor targeted probe design is a key to successfully deliver accurate information through many imaging modalities. When designing receptor targeted imaging probes, a variety of targeting receptors and imaging modalities are selected depending on type of cancer because overexpression of receptors are variant among tumors and each imaging modality has advantages and disadvantages. Subsequently selecting appropriate tumor targeting strategies is critical to efficiently visualize tumor of interest. In this review, we presented the strategies commonly used for designing receptor targeted probes and summarized the recent studies that implemented each strategies.