Pathogenic bacteria infection, which is an extremely serious clinical problem, could be effectively treated by the antibiotics, but the misuse of antibiotics caused by imprecise transportation is a huge problem that causes the emergence of multidrug-resistant bacteria, which can kill millions of people. Herein, a drug-carrier is developed that can deliver antibiotics precisely to the bacteria and kill bacteria efficiently, thus avoiding the misuse of antibiotics. These drug carriers, consisting of ciprofloxacin (cip)-loaded CaCO 3 coated by asymmetrical glycol chitosan (GCS) (cip-loaded CaCO 3 @GCS carriers, abbreviated as CC@GCs), could move autonomously in the acidic environment caused by the bacteria-infection, which is based on the asymmetric pressure generated by the CO 2 concentration gradient due to the asymmetric reaction between CaCO 3 and acid. The motion of CC@GCs increases its probability to contact the bacteria, leading to the formation of effective electrostatic binding between them. The combination of movement and enhanced affinity to bacteria enable CC@GCs to precisely deliver drug to bacteria and kill them more efficiently as compared to the free drug, which shows effective treatment in bacterial infection abscess on skin with improved drug utilization. The CC@GCs based drug carriers have great potentials in treating bacterial infection with precision for efficient antibacterial therapy and alleviating the antibiotic misusage.
To achieve better therapeutic outcomes in cancer treatment, the combination of radionuclide and chemotherapy is commonly employed in clinical practice. However, the primary challenge lies in achieving precise drug delivery to tumor tissues, often leading to suboptimal therapeutic efficacy. This study presents a novel, tumor microenvironment-responsive drug delivery carrier that integrates real-time MRI/SPECT dual-modal imaging for precise diagnosis and treatment monitoring. The carrier comprised is based on a hybrid structure composed of hyaluronic acid (HA) and human serum albumin (HSA), encapsulating the metal-organic framework MIL-100(Fe). It was loaded with the chemotherapeutic drug doxorubicin (DOX) and modified with the radionuclide 131 I, designed to precise diagnosis and treatment of tumors. HA binds specifically to the overexpressed CD44 receptor on the tumor surface, ensuring that the carrier targets tumors selectively. The incorporated 131 I emits β rays, which deliver ionizing radiation to eradicate tumor cells. Concurrently, the carrier could release DOX in response to the tumor microenvironment, inhibiting DNA synthesis and sensitizing the tumor cells to radiation. This combined approach results in synchronous radionuclide therapy (RNT) and chemotherapy, maximizing therapeutic impact. In vitro and in vivo experiments demonstrated that the carrier exhibited favorable biocompatibility, stable radionuclide labeling, tumor-specific accumulation, and controlled release of DOX within the tumor microenvironment. Furthermore, MRI/SPECT dual-modal imaging enabled real-time tumor localization and monitoring of the carrier in vivo biodistribution. Experimental outcomes confirmed that this innovative carrier, combining RNT and chemotherapy, significantly inhibited tumor growth. This strategy offers a promising approach for precision radio-chemotherapy guided by dual-modal imaging, providing valuable insights for integrated targeted diagnosis and treatment of tumors.
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