Targeted gene delivery to the synovial pannus in antigen-induced arthritis by ultrasound-targeted microbubble destruction in vivo

Local Renal Treatments for Acute Kidney Injury: A Review of Current Progress and Future Translational Opportunities

Acute kidney injury (AKI) constitutes a significant public health concern, with limited therapeutic options to mitigate injury or expedite recovery. A novel therapeutic approach, local renal treatment, encompassing pharmacotherapy and surgical interventions, has exhibited positive outcomes in AKI management. Peri-renal administration, employing various delivery routes, such as the renal artery, intrarenal, and subcapsular sites, has demonstrated superiority over peripheral intravenous infusion. This review evaluates different drug delivery methods, analyzing their benefits and limitations, and proposes potential improvements. Renal decapsulation, particularly with the availability of minimally invasive techniques, emerges as an effective procedure warranting renewed consideration for AKI treatment. The potential synergistic effects of combined drug delivery and renal decapsulation could further advance AKI therapies. Clinical studies have already begun to leverage the benefits of local renal treatments, and with ongoing technological advancements, these modalities are expected to increasingly outperform systemic intravenous therapy.

Role of Ultrasonic Microbubbles in Treating Rheumatoid Arthritis: Enhancing the Efficacy of Tocilizumab via Contrast-Enhanced Ultrasound-Monitored, Ultrasound-Targeted Microbubble Destruction

OBJECTIVE

Our aim was to explore the feasibility of using ultrasound-targeted microbubble destruction (UTMD) to deliver tocilizumab and enhance its efficacy in treating rheumatoid arthritis (RA).

METHODS

Rats with adjuvant-induced arthritis were randomly assigned to one of five treatment groups: group 1, tocilizumab + microbubbles (MBs) + UTMD; group 2, tocilizumab + MBs; group 3, tocilizumab + saline; group 4, MBs + UTMD; group 5, no treatment. We employed a commercially available ultrasound (US) machine capable of performing contrast-enhanced ultrasound (CEUS) and UTMD simultaneously using a single probe. CEUS was performed to monitor the entry and collapse of MBs. After treatment, the rats' left hindlimb paws were harvested for immunohistochemical staining of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α).

RESULTS

After injection of the mixture of drugs and MBs with UTMD, significant enhancement was seen in the inflamed hindlimb paw regions, which subsided immediately on exposure to low-frequency US beams and re-appeared in the intervals between beam exposures. IL-6 expression was significantly lower in groups 1, 2 and 3 than in groups 4 and 5 (p < 0.01). Group 1 had the lowest level of IL-6 expression (p [G1 vs. G2] < 0.01, p [G1 vs. G3] < 0.01). The levels of TNF-α expression in groups 1, 2, and 3 were significantly lower than those in groups 4 and 5, but no difference was observed in these levels between groups 1-3.

CONCLUSION

UTMD shows promise in enhancing the treatment efficacy of anti-IL-6 drugs for RA treatment.

Photoacoustic/ultrasound-guided gene silencing: Multifunctional microbubbles for treating adjuvant-induced arthritis

AIMS

To effectively deliver small interfering RNA (siRNA) to inflammatory tissues for treating rheumatoid arthritis (RA), we developed the multifunctional microbubbles (MBs) to perform photoacoustic/ultrasound-guided gene silencing.

METHODS

Fluorescein amidite (FAM)-labelled tumour necrosis factor-α (TNF-α)-siRNA and cationic MBs were mixed to fabricate FAM-TNF-α-siRNA-cMBs. The cell transfection efficacy of FAM-TNF-α-siRNA-cMBs was evaluated in vitro on RAW264.7 cells. Subsequently, wistar rats with adjuvant-induced arthritis (AIA) were injected intravenously with MBs and simultaneously subjected to low-frequency ultrasound for ultrasound-targeted microbubble destruction (UTMD). Photoacoustic imaging (PAI) was utilized to visualize the distribution of siRNA. And the clinical and pathological changes of AIA rats was estimated.

RESULTS

FAM-TNF-α-siRNA-cMBs were evenly distributed within the RAW264.7 cells and significantly reduced TNF-α mRNA levels of the cells. For AIA rats, the entering and collapsing of MBs was visualized by contrast-enhanced ultrasound (CEUS). Photoacoustic imaging showed markedly enhanced signals following injection, indicating localization of the FAM-labelled siRNA. The articular tissues of the AIA rats treated with TNF-α-siRNA-cMBs and UTMD showed decreased TNF-α expression levels.

CONCLUSIONS

The theranostic MBs exhibited a TNF-α gene silencing effect under the guidance of CEUS and PAI. The theranostic MBs served as vehicles for delivering siRNA as well as contrast agents for CEUS and PAI.

Nano-Based Co-Delivery System for Treatment of Rheumatoid Arthritis

A systemic autoimmune condition known as rheumatoid arthritis (RA) has a significant impact on patients’ quality of life. Given the complexity of RA’s biology, no single treatment can totally block the disease’s progression. The combined use of co-delivery regimens integrating various diverse mechanisms has been widely acknowledged as a way to make up for the drawbacks of single therapy. These days, co-delivery systems have been frequently utilized for co-treatment, getting over drug limitations, imaging of inflammatory areas, and inducing reactions. Various small molecules, nucleic acid drugs, and enzyme-like agents intended for co-delivery are frequently capable of producing the ability to require positive outcomes. In addition, the excellent response effect of phototherapeutic agents has led to their frequent use for delivery together with chemotherapeutics. In this review, we discuss different types of nano-based co-delivery systems and their advantages, limitations, and future directions. In addition, we review the prospects and predicted challenges for the combining of phototherapeutic agents with conventional drugs, hoping to provide some theoretical support for future in-depth studies of nano-based co-delivery systems and phototherapeutic agents.

Evaluation of Liposome-Loaded Microbubbles as a Theranostic Tool in a Murine Collagen-Induced Arthritis Model

Rheumatoid arthritis (RA) is an autoimmune disease characterized by severe inflammation of the synovial tissue. Here, we assess the feasibility of liposome-loaded microbubbles as theranostic agents in a murine arthritis model. First, contrast-enhanced ultrasound (CEUS) was used to quantify neovascularization in this model since CEUS is well-established for RA diagnosis in humans. Next, the potential of liposome-loaded microbubbles and ultrasound (US) to selectively enhance liposome delivery to the synovium was evaluated with in vivo fluorescence imaging. This procedure is made very challenging by the presence of hard joints and by the limited lifetime of the microbubbles. The inflamed knee joints were exposed to therapeutic US after intravenous injection of liposome-loaded microbubbles. Loaded microbubbles were found to be quickly captured by the liver. This resulted in fast clearance of attached liposomes while free and long-circulating liposomes were able to accumulate over time in the inflamed joints. Our observations show that murine arthritis models are not well-suited for evaluating the potential of microbubble-mediated drug delivery in joints given: (i) restricted microbubble passage in murine synovial vasculature and (ii) limited control over the exact ultrasound conditions in situ given the much shorter length scale of the murine joints as compared to the therapeutic wavelength.

Experimental study of TNF-α receptor gene transfection by ultrasound-targeted microbubble destruction to treat collagen-induced arthritis in rats in vivo

Ultrasound-targeted microbubble destruction (UTMD) is a novel method for gene transfection. The aim of the present study was to identify the most suitable method of tumor necrosis factor (TNF)-α receptor (TNFR) gene transfection using UTMD for systemically treating a rat model of collagen-induced arthritis (CIA). Plasmids encoding the TNFR and enhanced green fluorescent protein (EGFP) with or without microbubbles were locally injected into the skeletal muscle and synovial membrane of CIA rats. The rats were divided into the following 6 groups: i) Group 1, plasmid + microbubble + ultrasound (muscle group); ii) group 2, plasmid + microbubble + ultrasound (joint group); iii) group 3, plasmid + ultrasound; iv) group 4, plasmid + microbubble; v) group 5, plasmid only and; vi) group 6, untreated controls. Rats were sacrificed at 2, 4 and 8 weeks of treatment. The transfection efficiency of the plasmids in the muscle or synovium was observed by fluorescence microscopy. Arthritis scores were calculated and serum levels of TNF-α were measured prior to and following treatment. Bilateral ankle joints were obtained and stained to observe synovial inflammation and the expression of TNF-α. EGFP expression was detected in all treated groups at each time point, and the fluorescence intensity of groups 1 and 2 was significantly greater than that of the other groups (P<0.05). For groups 1 and 2, the reductions in joint scores and serum levels of TNF-α were significant compared with the other groups (P<0.05). The number of synovial inflammatory cells and the synovial expression of TNF-α presented similar results among all experimental groups and no significant difference was observed between groups 1 and 2. Therefore, the results of the present study suggest that UTMD significantly enhanced the efficiency of TNFR gene transfection in the muscle and inflamed synovium of rats with. Regardless of whether the transfected TNFR gene was injected into the muscle or joint, it was continuously expressed in the rats for at least 8 weeks, which may improve arthritic symptoms and reduce the levels of inflammatory factors in the synovial tissues and peripheral blood.