Small-Molecule Boron-10-Enriched Carriers with Exceptional Aqueous Solubility for Enhanced Boron Neutron Capture Therapy of Malignant Tumors

  • Research (Wash D C). 2026 Jul 3:9:1315. doi: 10.34133/research.1315.
Tongyin Xiong  1  2 ,  Xiangdi Yang  1 ,  Tingting Li  1 ,  Rongtao Song  1  2 ,  Linxuan Huang  1 ,  Xueli Sang  1 ,  Fang Hu  2 ,  Xiao Xu  1 ,  Zhigang Liu  1
Affiliations
  • 1. Cancer Center, Guangdong Engineering Research Center of Boron Neutron Therapy and Application in Malignant Tumors, Dongguan Key Laboratory of Precision Diagnosis and Treatment for Tumors, The Tenth Affiliated Hospital, Southern Medical University (Dongguan People's Hospital), Dongguan 523059, China.
  • 2. Biomaterials Research Center, School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medial Image Processing, Southern Medical University, Guangzhou 510515, China.
PMID: 42404354 DOI: 10.34133/research.1315
Abstract

Boron neutron capture therapy (BNCT) enables localized tumor ablation while minimizing damage to surrounding tissues, offering advantages for treating anatomically challenging sites. However, current boron carriers, such as sodium borocaptate (10BSH), suffer from inadequate tumor specificity. Herein, the present study details the design, synthesis, and preclinical evaluation of a novel small-molecule boron-10-enriched carrier, which was synthesized by covalent bond coupling 4-carboxy-3-fluorophenylboronic acid (FPBA) to 10BSH (FPBA-BSH), achieving a boron content of approximately 25 wt.%. FPBA-BSH efficiently penetrated the blood-brain barrier and demonstrated pronounced accumulation in orthotopic gliomas, achieving a boron concentration of 75.4 μg-B/g-tumor tissue, which was 4.2- and 3.7-fold higher than those with boronophenylalanine (BPA) and BSH, respectively. Moreover, FPBA-BSH exhibited markedly improved tumor selectivity, with tumor-to-normal tissue (T/N) and tumor-to-blood ratios of 52.0 and 7.2, respectively. The T/N ratio was approximately 19.3- and 14.1-fold greater than those observed for BPA and BSH. In the melanoma model, FPBA-BSH achieved an intratumor boron concentration of 114.4 μg-B/g-tumor tissue, representing 8.4- and 9.9-fold increases compared with BPA and BSH, respectively. Correspondingly, the T/N and tumor-to-blood ratios reached 135.1 and 8.6, indicating substantially enhanced tumor targeting and retention. The T/N ratio achieved with FPBA-BSH was approximately 26.0- and 34.6-fold higher than those obtained with BPA and BSH, respectively. Consistent with its superior tumor selectivity, FPBA-BSH-mediated BNCT induced pronounced tumor-selective cytotoxicity and markedly inhibited tumor growth in both orthotopic glioma and melanoma models compared with BPA, BSH, and untreated controls. These findings demonstrate that FPBA-BSH represents a promising small-molecule boron delivery agent with substantial potential for clinical BNCT applications.

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