Otitis media (OM) is a common disease in children. One of the most common pathogens causing OM is non-typeable Haemophilus influenzae (NTHi). NTHi in the middle ear can be successfully eradicated by a regimen of oral antibiotics sustained for 7–10 days (e.g., cefuroxime axetil 250 mg/day for patients aged 3 months to 2 years and 500 mg/day for patients ages ≥2 years). However, lack of compliance is relevant to treatment failure or early relapse. In order to overcome these challenges, we have developed antibiotics-loaded bioadhesive nanoparticles (BNPs) that can adhere to the epidermis of the middle ear after local administration and significantly prolong the release time of antibiotics in the middle ear. Compared with oral administration of CA, local delivery of free antibiotic cefuroxime axetil (CA), and CA loaded non-bioadhesive nanoparticles (CA/NNPs), BNPs loaded with cefuroxime axetil (CA/BNPs) showed significantly longer retention time in the middle ear, resulting in continuous release of the drug and higher therapeutic efficacy against OM with only a single dosage. CA concentrations were maintained above the minimum inhibitory concentration (MIC) for NTHi throughout 7 days’ treatment. NTHi OM in a mouse model was successfully eradicated without causing tissue toxicity. CA/BNPs minimize systemic drug exposure through local administration, as demonstrated by undetectable levels in the blood.

Detection of circulating tumor cells (CTCs) could be widely used for early diagnosis and real-time monitoring of tumor progression in liquid biopsy samples. Compared with normal cells, tumor cells exhibit relatively strong negative surface charges due to the high rate of glycolysis. In this study, a cationic fluorescence “turn-on” aggregation-induced emission (AIE) nanoprobe based on gold nanorods (GNRs) was designed and tested to detect tumor cells specifically. In brief, tetraphenylethene (TPE), an AIE dye, was conjugated to the cationic polymer polyethylenimine (PEI) yielding TPEI. TPEI-PEG-SH was obtained by further functionalizing TPEI with a thiol group. TPEI-PEG-SH was grafted to the surface of GNRs, yielding the cationic AIE nanoprobe, named as GNRs-PEG-TPEI. The nanoprobe was characterized to have a uniform particle size of 172 nm, a strong positive surface charge (+54.87 mV), and a surface modification load of ∼40%. The in vitro stability of GNRs-PEG-TPEI was verified. The cellular imaging results demonstrated that the nanoprobe could efficiently recognize several types of tumor cells including MCF-7, HepG2, and Caco-2 while exhibiting specific fluorescence signals only after interacting with tumor cells and minimal background interference. In addition, the study investigated the toxicity of the nanoprobe to the captured cells and proved the safety of the nanoprobe. In conclusion, a specific and efficient nanoprobe was developed for capture and detection of different types of tumor cells based on their unique metabolic characteristics. It holds great promise for achieving early diagnosis and monitoring the tumor progression by detecting the CTCs in clinical liquid biopsy samples.