Purpose: The phase II/III study of donafenib was initiated when there was no available treatment indicated for Chinese patients with progressive radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC). Donafenib, an oral tyrosine kinase inhibitor (TKI), showed good efficacy and tolerability in the phase II study. We aimed to further evaluate the antitumor activity and safety of donafenib in Chinese patients with RAIR-DTC. Patients and Methods: This multicenter, double-blind, placebo-controlled, phase III study enrolled 191 patients with progressive RAIR–DTC and randomized in a ratio of 2:1 to donafenib (300 mg twice daily, n = 128) or matched placebo (n = 63). An open-label donafenib treatment period was allowed upon disease progression. The primary endpoint was progression-free survival (PFS) assessed by the independent review committee. The second endpoints include objective response rate (ORR), disease control rate (DCR), safety, etc. Results: Donafenib demonstrated prolonged median PFS over placebo [12.9 vs. 6.4 months; hazard ratio (HR), 0.39; 95% confidence interval (CI), 0.25–0.61; P < 0.0001] in Chinese patients with RAIR–DTC. Improved ORR (23.3% vs. 1.7%; P = 0.0002) and DCR (93.3% vs. 79.3%; P = 0.0044) were observed in the donafenib group over placebo. For donafenib, the most common grade ≥ 3 treatment-related adverse events (AE) included hypertension (13.3%) and hand–foot syndrome (12.5%), 42.2% underwent dose reduction or interruption, and 6.3% experienced discontinuation. Conclusions: Donafenib was well-tolerated and demonstrated clinical benefit in terms of improved PFS, ORR, and DCR in patients with RAIR-DTC. The results suggest that donafenib could be a new treatment option for patients with RAIR-DTC.

Background: Successful engraftment and localization of mesenchymal stem cells (MSCs) within target tissues are critical factors influencing their therapeutic efficacy for tissue repair and regeneration. However, the relative contributions of biophysical factors like cell size and adhesion capacity in regulating MSC distribution in vivo remain incompletely understood. Methods: Cell adhesion peptides and hanging drop method were used to modify the adhesive capacity and size of MSCs. To quantitatively track the real-time biodistribution of transplanted MSCs with defined size and adhesion profiles in living mice and rats, the non-invasive positron emission tomography (PET) imaging was applied. Results: Surface modification with integrin binding peptides like RGD, GFOGER, and HAVDI reduced MSC adhesion capacity in vitro by up to 43.5% without altering cell size, but did not significantly decrease lung entrapment in vivo. In contrast, culturing MSCs as 3D spheroids for 48 h reduced their cell diameter by 34.6% and markedly enhanced their ability to pass through the lungs and migrate to other organs like the liver after intravenous administration. This size-dependent effect on MSC distribution was more pronounced in rats compared to mice, likely due to differences in pulmonary microvessel diameters between species. Conclusion: Our findings reveal that cell size is a predominant biophysical regulator of MSC localization in vivo compared to adhesion capacity, providing crucial insights to guide optimization of MSC delivery strategies for enhanced therapeutic efficacy. Graphical

Cerenkov radiation-induced photodynamic therapy (CR-induced PDT) has shown the potential to overcome the light penetration limitation in conventional PDT. In addition, the tumor-associated antigens (TAAs) produced by PDT can initiate an antitumor immune process but only show a limited immunotherapeutic effect without the use of immunotherapeutic agents. Herein, a CR-induced PDT hydrogel (R837/⁸⁹Zr-HG-PpIX) has been developed by in situ formation of a hyaluronic acid (HA)-based hydrogel integrated with internal light source ⁸⁹Zr, photosensitizer protoporphyrin IX (PpIX), and immune adjuvant imiquimod (R837). The obtained R837/⁸⁹Zr-HG-PpIX hydrogel with long-term tumor retention and low radiation leakage can provide long-lasting photodynamic therapy without phototoxicity in normal tissues. In addition, the loaded R837 improves the immunogenicity of TAAs released after PDT, resulting in considerably enhanced immune responses. At relatively low radioactivity, R837/⁸⁹Zr-HG-PpIX shows significant inhibition in subcutaneous H22 tumor-bearing BALB/c mice and orthotopic VX2 liver tumor-bearing rabbits. Furthermore, the combination of such a CR-induced PDT hydrogel with anti-PD-L1 exhibits the abscopal effect to inhibit the growth of distant tumors. Therefore, the proposed in situ formed CR-induced PDT hydrogel with long-term photodynamic-immunotherapy provides an effective strategy for deep tumor therapy.

Protein kinase C-dependent activation of P44/42 mitogen-activated protein kinase and heat shock protein 70 in signal transduction during hepatocyte ischemic preconditioning