Temporal barriers against hypersensitivity response: from degradable polymer photoreduction

Stimuli-responsive materials caused great concern in the past few decades. Have been based on a variety of polymeric drug carrier of endogenous and exogenous stimuli is designed. Wherein for pH, redox enzymes and the endogenous physiological stimuli responsive polymer having a nano-system has a high application value in drug and gene delivery and the like, in recent years become a materials science, biomedical and pharmaceutical field research focus. However, these bio-responsive polymer material effect in vivo application faces many challenges. First, endogenous stimuli in a heterogeneous distribution, and as the disease progresses and constantly changing, leading to specific stimulation response is not satisfactory in different individuals, tissues and organs. Second, since stimulating factor complex, and the different cell organelles an organism and is changing dynamically unbalanced state. In addition, reaction was continued for a biological system and responsive material body may further consume stimuli, resulting in decreased response efficiency. More importantly, most of the stimuli-responsive polymer nano materials sensitive groups in its hydrophobic core shielded or protected housing, the water supply position to bring molecules, glutathione (of GSH), enzymes and other biological macromolecules attack resistance barrier. Therefore, of great significance novel design of smart materials to overcome time and space barriers stimulate a response.

Figure 1. A schematic diagram of the light reduction from polymer degradation

Recently, Professor Ding Mingming College of Polymer Science and Engineering, Sichuan University, , Prof. Fu Qiang and Professor Tam Hong designed a since the light reducing Biodegradable polymer (PRSRP) , and reducing the stimulus sensitive groups together \”locked\” molecular \”cage\”, and using a light-sensitive group \”lock\” live stimuli. The photoreduction lesions from Biodegradable Polymer in response to a physiological environment can be realized intracellular levels of glutathione broken backbone. In the absence of a reducing agent, the polymer in situ by light \”unlocked\” reducing groups, to achieve reduction of the main chain from degradation, thereby overcoming obstacles temporal response stimuli, stimuli sensitive polymer to improve the response rate ( figure 1). To implement this strategy, research team first synthesized amphiphilic PRSRP different molecular weights, to form a layer of self-assembly found vesicular structures (FIG. 1) by a multi-stage in an aqueous solution. In situ FTIR, 1H NMR, GPC, and applied to study the mechanism MS photoreduction and products from degradation. Degradation of PRSRP using Spectra UV-Vis absorption kinetics, self-assembly found that the polymer has a faster degradation rate than the solution. Demonstrated using a fluorescent model drug responsive polymer having a more efficient drug release performance (FIG. 2) as compared to a conventional reduction of the light-sensitive PRSRP and self-assembly.

Figure 2. The stimulus responsive performance and drug release PRSRP the

Further aspects of the study of the potential delivery of the drug intracellularly PRSRP found PRSRP anticancer drug doxorubicin can be carried Su enter tumor cells efficiently while maintaining complete self-assembled structure. In the light conditions, the nanocarrier in the cell in response to the performance of sensitive and rapid release of surplus properties, reduce the% inhibition more than four times. Further, PRSRP having good cell compatibility, but also reduction of the light to be readily degraded by small molecules clearance and metabolism, have a greater prospect in vivo. This overcomes the problems of steric study disorders, disorders osmotic stimuli responsive through molecular design, while avoiding the limitations of conventional light degradable polymer main chain is introduced need complex light-sensitive groups like, thus this strategy readily extended to other material systems , smart responsive polymer material is designed to provide a new idea.

Figure 3. The self-assembly PRSRP intracellular drug delivery properties

In the above related outcomes \”Photo-ResponsiveSelf-Reducible Polymers: Overcoming the Spatiotemporal Barriers for Hypersensitivity\” was published in the \”ACS Materials Letters\” journals. The first author of the paper for the of Sichuan University graduate Weng master Chuang , co-corresponding author for the Professor Ding Mingming and Professor Fu Qiang . The research work was supported by the National Natural Science Foundation of China (51873118,21474064,51203101), National Outstanding Youth Science Foundation of China (51425305) and the State Key Laboratory of PolymerFunded project room. Article link: https: //doi.org/10.1021/acsmaterialslett.0c00070