6.5.10 Application of nano-polymer drug carriers i...
polymer nanomaterials can load drugs and use their targeting ability to improve the residence time of drugs in lesions，and as chemical enhancers to improve the diffusion efficiency of drugs.Studies have shown that in the inflammatory skin environment of psoriasis，CD44 protein is highly expressed，while the expression of its corresponding hyaluronic acid（HA）is decreased.Therefore，CD44 can be used as a target of polymer nano-drug carriers.Feng et al.prepared a conjugate of HA and phospholipid molecules and constructed a curcumin-loaded polymer nano-drug carriers（Figure 6-11（a））.Curcumin can inhibit the proliferation of skin keratinocytes.HA can target CD44，thus，polymer nanodrug carriers with conjugated HA on surfaces have a higher targeting ability than HA free polymer nano-drug carriers，which improves the enrichment of curcumin in the skin and the therapeutic effect of curcumin on psoriasis.In addition to CD44 targeting，HA has excellent water-absorbing and moisturizing properties.Vicent et al.prepared the polymer nano-drug delivery system（Figure 6-11（b））by co-assembly of poly-L-glutamate（PGA）with conjugated psoriatic drug，fluocinolone acetonide，and HA-PGA.The drug delivery system have greater skin penetration depth than a PGA-drug conjugate.The mechanism may be related to the increase of water content in stratum corneum and epidermis due to the water absorption of HA.Under the combined action of acid and enzyme，the drug can be released from the carriers to achieve the treatment of psoriasis.(https://www.daowen.com)