Superhydrophobic Materials for Tunable Drug Release: Using Displacement of Air To Control Delivery Rates

Abstract

We have prepared 3D superhydrophobic materials from biocompatible building blocks, where air acts as a barrier component in a porous electrospun mesh to control the rate at which drug is released. Specifically, we fabricated poly(ε-caprolactone) electrospun meshes containing poly(glycerol monostearate-co-ε-caprolactone) as a hydrophobic polymer dopant, which results in high apparent contact angle meshes. We demonstrate that the apparent contact angle of these meshes dictates the rate at which water penetrates into the porous network and displaces entrapped air. Addition of a model bioactive agent (SN-38) shows a release rate with a striking dependence on apparent contact angle which can be explained by this displacement of air within the electrospun meshes. We further show that porous, higher surface area electrospun meshes can be prepared to release more slowly than control non-porous constructs. Finally, the entrapped air layer within superhydrophobic meshes is shown to be robust in the presence of serum, where drug loaded meshes are efficacious against cancer cells in vitro for >60 days, thus demonstrating applicability for long-term drug delivery.

Designing durable and flexible superhydrophobic coatings and its application in oil purification

“…Superhydrophobic surfaces that exhibit extreme water-repellent properties are both of scientific and industrial interest, due to their use in a range of applications, such as in water/oil separation, [1][2][3] anti-icing, [4][5][6] self-cleaning, 7,8 drug release, 9,10 and drag reduction in fluids. [11][12][13] Inspired by Lotus leaves, 14,15 Salvinia, 16 seaweed 17 and other species in nature, [18][19][20][21][22] a variety of man-made approaches have been pursued to mimic those surfaces to create artificial superhydrophobic surfaces.…”

Polydimethylsiloxane–Indomethacin Blends and Nanoparticles

“…According to literature data (30), more interesting results could be expected for transdermal applications or implantable devices and drug release enhancers can improve the results significantly (7). It was established that hydrophobic polymers are able to release drugs very slowly, thus being efficient in cancer treatment, for example (31). The lack of physical or chemical interactions between the matrix and the drug as well as the propensity for phase separation, are important aspects that have to be taken into account in drug delivery applications involving PDMS.…”

Biological Applications of Biomimetic Superhydrophobic Surfaces

“…迄今为止利用超疏水材料来控制 药物输送的文献相对较少, 但其潜在的优势如长期给 药、生物相容性好等终将使其作为一种新的控制药物释 放体系而引起各国研究人员的广泛关注, 此领域将会成 为一段时间内超疏水应用的一个研究热点. 图 3 (a) 超疏水网格纤维 [48] ; (b) 药物在三维超疏水材料释放的机理 [48] : (c, d) 分别担载 SN-38 和 CPT-11 的超疏水网格的控制释放曲线图 [49] Figure 3 (a) 10% PGC-C18-doped electro-spun PCL mesh with an average fiber size of 7.2±1.4 μm; (b) Proposed mechanism of drug-eluting 3D superhydrophobic materials [48] ; (c) SN-38 release profiles from electro-spun meshes with 1 wt% SN-38; (d) CPT-11 release profiles from electro-spun meshes with 1 wt% CPT-11 [49] [55] 通过实验验证了这一结果(图 4b). 然而在极端润湿性的情况下, 蛋白质吸附却表现 出截然不同的情况 [56,57] .…”