Polyamidoamine dendrimer-conjugated triamcinolone acetonide attenuates nerve injury-induced spinal cord microglia activation and mechanical allodynia. Issue 1 (March 2017)

• Record Type: Journal Article
• Authors: Kim, Hwisung; Choi, Boomin; Lim, Hyoungsub; Min, Hyunjung; Oh, Jae Hoon; Choi, Sunghyun; Cho, Joung Goo; Park, Jong-Sang; Lee, Sung Joong
• Is Part Of: Molecular pain. Volume 13:Issue 1(2017)
• Publication Date: 2017-03
• Subjects: Dendrimer-triamcinolone acetonide -- neuropathic pain -- peripheral nerve injury -- spinal cord microglia; Pain -- Molecular aspects -- Periodicals; Pain -- Pathophysiology -- Periodicals; Pain -- Physiological aspects -- Periodicals; 616.0472
• DOI: 10.1177/1744806917697006
• Languages: English
• ISSNs: 1744-8069

Abstract

Background: Accumulating evidence on the causal role of spinal cord microglia activation in the development of neuropathic pain after peripheral nerve injury suggests that microglial activation inhibitors might be useful analgesics for neuropathic pain. Studies also have shown that polyamidoamine dendrimer may function as a drug delivery vehicle to microglia in the central nervous system. In this regard, we developed polyamidoamine dendrimer-conjugated triamcinolone acetonide, a previously identified microglial activation inhibitor, and tested its analgesic efficacy in a mouse peripheral nerve injury model. Result: Polyamidoamine dendrimer was delivered selectively to spinal cord microglia upon intrathecal administration. Dendrimer-conjugated triamcinolone acetonide inhibited lipoteichoic acid-induced proinflammatory gene expression in primary glial cells. In addition, dendrimer-conjugated triamcinolone acetonide administration (intrathecal) inhibited peripheral nerve injury-induced spinal cord microglial activation and the expression of pain-related genes in the spinal cord, including Nox2, IL-1β, TNF-α, and IL-6. Dendrimer-conjugated triamcinolone acetonide administration right after nerve injury almost completely reversed peripheral nerve injury-induced mechanical allodynia for up to three days. Meanwhile, dendrimer-conjugated triamcinolone acetonide administration 1.5 days post injury significantly attenuated mechanical allodynia. Conclusion: Our data demonstrate that dendrimer-conjugated triamcinolone acetonide inhibits spinal cord microglia activation and attenuates neuropathic pain after peripheral nerve injury, which has therapeutic implications for the treatment of neuropathic pain.