Bio-Inspired Degradable Polyethylenimine/Calcium Phosphate Micro-/Nano-Composites for Transient Ultrasound and Photoluminescence Imaging

Abstract

Inorganic nanomaterials hold immense potential in theranostics, but their translation is limited by the toxicity resulting from non-degradability. Bulk phosphate-based glasses offer great biodegradability, biocompatibility, and ease in incorporating imaging dyes and drugs. However, the facile and mild solution-based synthesis of micro-/nanoparticles of this material is yet to be explored. Inspired by the biosilicification process in the diatom, we created polyethylenimine (PEI)/phosphate aggregates via the hydrogen bonding between amine (PEI) and hydroxyl (phosphate) groups, which was proved by dynamic light scattering and 1 H solution nuclear magnetic resonance. The sol−gel reaction between the calcium precursor and PEI/phosphate aggregates yielded degradable PEI/ calcium phosphate (PEI/CP) micro-/nano-composites with versatile sizes (396 ± 128 nm to 63 ± 8 μm) and morphologies (hexagonal micro-disc, micro-flower, micro-leaf, nano-butterfly, and nanoribbon). The PEI/CP composition and chemical structure were examined. PEI/CP has negligible cell cytotoxicity and degrades within 24 h. In vitro studies showed the promise for PEI/CP in transient ultrasound and photoluminescence imaging.

Biogenic polymer nanoparticles to remove hydrophobic organic contaminants from water

“…However, the presence of oxidizable functional groups permits hydrolysis and enzymatic biodegradation of backbone synthetic polymers such as polyurethanes, polyanhydrides, polyesters, etc. He et al have created polyethylenimine)/phosphate aggregates forming hydrogen bonding between amine and hydroxyl groups, it has produced degradable microÀ/nano-composites suitable for various applications (He et al, 2022). Matsuzawa et al have studied the sorption properties of biodegradable polyesters using several aromatic chemicals as models for hydrophobic organic contaminants (HOCs).…”

Peptide‐Driven Proton Sponge Nano‐Assembly for Imaging and Triggering Lysosome‐Regulated Immunogenic Cancer Cell Death

“…Interestingly, low‐molecular‐weight branched PEI (lwPEI, e.g., 800 Da) is not toxic due to a lower buffering capacity compared to hwPEI. [ 19b,20 ] We hypothesized that the positive surface charge density of lwPEI would be enhanced when lwPEI underwent self‐assembly to form “high molecular weight” nanoparticles, causing a dramatic enhancement in lysosome rupturing capability, cell cytotoxicity, and capacity of triggering immunogenic cancer cell death. Enabling this self‐assembly‐dependent cytotoxicity of lwPEI would pave the way for the future innovation of a nanomedicine with a tumor activatable killing effect and immunogenicity by further rendering the self‐assembly activatable by tumors.…”

Lipid-inspired biomimicking morphosynthesis of a series of complex concave silica architectures

“…The interactions between silicate species and 1 via electrostatic and/ or hydrogen bonding interactions disrupt the intermolecular hydrogen bonding of 1 among the sugar headgroups and amide units, resulting in a conformational transition of 1 from a tube-to-coil conformational transition. As 1 contains precisely positioned hydroxyl (-OH) groups from sugar headgroups, which are important for biosilicification processes, 24 a cooperative effect may then arise between the silica and 1 to direct the formation of the thin circular nanosheet consisting of a silica-1 hybrid in the early time of silica mineralization. Embedding of 1 allows this hybrid sheet to be soft and elastic, and it can deform easily.…”