In the present study, we used CaCO3 nanoparticles (CCNPs) as carriers to assess the physicochemical characteristics and antibacterial effect of gentamicin sulfate (GS)-loaded CCNPs (CGPs). The results indicated that CCNPs had relatively regular chain-like structure, and the size of the crystallites was around 62.5 nm. FT-IR analysis indicated that the GS could effectively load onto CCNPs. Meanwhile, the dosage of CCNPs would affect the drug loading and entrapment efficiency of GS. CCNPs could prolong the release of GS, and the complete release of GS from CCNPs was extended up to 24 h. Additionally, CCNPs could obviously increase the antibacterial effect of GS. The zeta potential analysis and microscopic investigations indicated that the adsorbed CCNPs could increase the damage level of bacterial cell wall and enhance the permeability of cell membranes, leading to increased bacterial death.

The engineering of pharmaceutical cocrystals has been effectively utilized to improve the physicochemical properties such as stability and solubility, and thus it could optimize the solid formations of active pharmaceutical ingredients. This work focuses on the sulfamethazine–p-aminobenzoic acid (STH–PABA) cocrystal regulated by molecular synthons constructed from mutual N···H···O interactions. The STH–PABA cocrystal was produced by means of the slow evaporation crystallization method, and the cocrystal structure was determined through X-ray crystallography. Meanwhile, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman, and NMR were applied to analyze the features of the STH–PABA cocrystal. Special attention was paid to in vitro antibacterial activity and microscopic investigations. Our findings indicated that the formation of cocrystals could enhance the solubility and slightly improve the release behavior of STH, and increase the leaking of bacterial cell inclusion that leads to enhanced antibacterial activity.

The traditional Bacillus thuringiensis (Bt) formulations for field applications are not resistant to harsh environmental conditions. Hence, the active ingredients of the Bt bioinsecticides could degrade quickly and has low anti-ultraviolet ability in the field, which significantly limits its practical application. In the present study, we developed an efficient and stable delivery system for Bt Cry11Aa toxins. We coated Cry11Aa proteins with Mg­(OH)2 nanoparticles (MHNPs), and then assessed the effects of MHNPs on bioactivity and anti-ultraviolet ability of the Cry11Aa proteins. Our results indicated that MHNPs, like “coating clothes”, could effectively protect the Cry protein and enhance the insecticidal bioactivity after UV radiation (the degradation rate was decreased from 64.29% to 16.67%). In addtion, MHNPs could improve the proteolysis of Cry11Aa in the midgut and aggravate the damage of the Cry protein to the gut epithelial cells, leading to increased insecticidal activity against Culex quinquefasciatus. Our results revealed that MHNPs, as an excellent nanocarrier, could substantially improve the insecticidal bioactivity and anti-ultraviolet ability of Cry11Aa.

Bacillus thuringiensis (Bt) can produce Cry proteins during the sporulation phase, and Cry protein is effective against lepidopteran, coleopteran, and dipteran insects and nematodes. However, Cry protein tends to be discharged into soil and nontarget plants through rainwater runoff, leading to reduced effective period toward target insects. In the present study, nano-Mg(OH) (magnesium hydroxide nanoparticles, MHNPs) were synthesized to control the loss of Cry1Ac protein and deliver protein to Helicoverpa armigera (Lepidoptera: Noctuidae). The results showed that Cry1Ac protein could be loaded onto MHNPs through electrostatic adsorption, and both MHNPs and Cry protein were stable during the adsorption process. Meanwhile, the Cry1Ac-loaded MHNPs could remain on the surface of cotton leaves, resulting in enhanced adhesion of Cry1Ac protein by 59.50% and increased pest mortality by 75.00%. Additionally, MHNPs could be slowly decomposed by acid medium and MHNPs showed no obvious influence on cotton, Bt, Escherichia coli, and H. armigera. Therefore, MHNPs could serve as an efficient nanocarrier for delivery of Cry1Ac protein and be used as a potential adjuvant for biopesticide in agricultural applications.