Decorated nanogels as promising tools for selective drug delivery in spinal cord injury

Introduction

Spinal cord injury (SCI) is characterized by a primary SCI that is the consequence of a traumatic event, and by the subsequent inflammatory response, characterized by the activation of microglia/macrophages/astrocytes, that leads to an aggravation of the pathology and to neurodegeneration [1,2]. A possible therapeutic approach is represented by the possibility to modulate the inflammatory response through the release of drugs in the damaged zone selectively within different cell lines. Recent advances in polymer science and nanotechnologies showed increased interest for nanogels (NGs), a new class of colloidal systems that can be used as carriers to treat SCI.

Material and Methods

Nanogels were synthesized using polyethylene glycol (PEG) and polyethylenimine linear (PEI), after having functionalized PEI with a chromophore [3, 4]. This PEI functionalization was essential to constantly trace the nanogels during the biological assays. Many different coating strategies of the nanogels were analyzed; in fact, surface functionalization is essential to tune the characteristics and the biological behavior of the final system.

Results and discussion

Biological tests proved that functionalized nanogels were able to be selectively internalized in mouse microglia or astrocytes depending on their surface decoration, that their degradation promoted drug release, and that the use of anti-inflammatory molecules as a delivered drug were able to mitigate the pain state [5, 6]. Subsequent in vivo assays on diseased mice confirmed the result obtained in vitro and the potentiality of this kind of surface functionalization.

Conclusions

Nanogels are, for sure, effective devices in drug delivery, and here, we showed their potentialities as targeted drug delivery systems in SCI.

References

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[2] J. Control. Release. 2021, 330, 218.

[3] Coll. Surf. A. 2021, 614, 126164.

[4] Coll. Surf. A. 2023, 658, 130623.

[5] ACS Nano. 2020, 14, 360.

[6] ACS Nano. 2013, 7, 9881.