Wound dressing with the capacities of antioxidation, antiinflammation, and efficient angiogenesis induction is expected for effectively promoting wound healing. Herein, a novel core‐shell hyaluronic acid (HA) microneedle (MN) patch with ferrum‐mesenchymal stem cell‐derived artificial nanovesicles (Fe‐MSC‐NVs) and polydopamine nanoparticles (PDA NPs) encapsulated in the needle tips is presented for wound healing. Fe‐MSC‐NVs containing multifunctional therapeutic cytokines are encapsulated in the inner HA core of the MN tips for accelerating angiogenesis. The PDA NPs are encapsulated in the outer methacrylated hyaluronic acid (HAMA) shell of the MN tips to overcome the adverse impacts from reactive oxygen species (ROS)‐derived oxidative stress. With the gradual degradation of HAMA patch tips in the skin, the PDA NPs are sustainably released at the lesion to suppress the ROS‐induced inflammation reaction, while the Fe‐MSC‐NVs significantly increase the migration, proliferation, and tube formation of human umbilical vein endothelial cells (HUVEC). More attractively, the combination of PDA NPs and Fe‐MSC‐NVs further promotes M2 macrophage polarization, thereby suppressing wound inflammation. Through in vivo experiment, the Fe‐MSC‐NVs/PDA MN patch shows an excellent effect for diabetic wound healing. These features of antioxidation, antiinflammation, and pro‐angiogenesis indicate the proposed composite core‐shell MN patch is valuable for clinical wound healing applications.
Mesenchymal stem cells derived exosomes (MSC‐exos) exhibit an intrinsic and directed efficiency for multiple diseases, while their versatile and effective delivery to the target site is still a challenge. Herein, inspired by the acids and enzymes resistant property of sealing gelatin capsules, novel MSC‐exo‐encapsulated oral microcapsules are presented for colitis treatment. Based on a microfluidic electrospray technique, MSC‐exos are first encapsulated in sodium alginate (SA) hydrogel microspheres with sustainable bioactivity. The resultant SA microspheres are then coated with a middle gelatin layer to protect MSC‐exos from degradation. Especially, with an enteric coating‐Eudragit FS30D on the outer layer, the resistance of the microcapsules in gastric juice is further enhanced. The prepared microcapsules maintain the stability and bioactivity of the MSC‐exos during storage, protect them from the harsh conditions in the gastrointestinal tract, and enable the release of actives in the suitable sites for exerting their biological functions. In addition, these MSC‐exos encapsulated microcapsules reduce the proinflammatory cytokines levels of inflammatory macrophages and impaired colonic epithelial cells, which exhibit superior damage repair ability in injured colon sites. Thus, it is believed that the proposed oral MSC‐exos encapsulated microcapsules are valuable for many practically clinical treatments.
This study is designed to compare drug encapsulation
by cucurbit[7]uril
and β-cyclodextrin, using fluorofenidone as a model drug. Single-crystal
X-ray diffraction analysis was employed to successfully determine
the crystal structures of fluorofenidone·H+@cucurbit[7]uril
Form, fluorofenidone@cucurbit[7]uril Form, and fluorofenidone@β-cyclodextrin
Form. Keto–enol tautomerization of fluorofenidone mediated
by cucurbit[7]uril in acid solution is confirmed by crystal structures,
pH titration, and nuclear magnetic resonance experiments. However,
β-cyclodextrin cannot cause the keto–enol tautomerization
of fluorofenidone under similar conditions. The phase solubility study
demonstrates that cucurbit[7]uril has a much higher solubilization
capacity for fluorofenidone than β-cyclodextrin in 0.1 M HCl
since the K
c values of fluorofenidone
with cucurbit[7]uril and β-cyclodextrin were 1223.97 ±
452.68 and 78.49 ± 10.56 M–1, respectively.
Excellent solubility can be attributed to the keto–enol tautomerization
of fluorofenidone under the conditions of cucurbit[7]uril in acid
solution. The enol form of fluorofenidone is encapsulated by cucurbit[7]uril
by hydrogen bonding interaction and hydrophobic interaction to increase
binding affinity. Rat pharmacokinetic studies demonstrate that the
area under the plasma concentration–time curve from time 0
to 7 h value of fluorofenidone@cucurbit[7]uril complex is 1.70-fold
greater than that of free fluorofenidone, and the mean residence time
from time 0 to 7 h is slightly prolonged from 1.29 to 1.76 h (P < 0.01) after oral administration. However, no significant
difference is found between fluorofenidone and fluorofenidone@β-cyclodextrin
complex. This work indicates that the induction of keto–enol
tautomerization of drugs using macrocyclic molecules has the potential
to be an effective method to improve their solubility and bioavailability,
providing valuable insights for the application of macrocyclic molecules
in the biomedical field.
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