Low molecular weight heparin (LMWH) plays an important role in the prevention and treatment of venous thromboembolism. Sensitive and facile monitoring of LMWH is of great significance for clinical special populations. Herein, using enoxaparin (Enox) as the typical representative of LMWH, a convenient and accurate fluorescence method was developed for Enox detection using carbon dots with antioxidant activity (A-CDs) as probe and polymyxin B (PMB) as medium agent. Compared with the simple Enox or PMB, the formed complex of PMB and Enox (PMB-Enox) based on the electrostatic interaction exhibited a new absorbance peak at 340 nm. Correspondingly, the absorbance of PMB-Enox overlapped with the exciting wavelength of A-CDs at 350 nm and effectively quenched the fluorescence of A-CDs through inner filter effect (IFE). The decreased fluorescence intensities of A-CDs were controlled by the increased Enox with constant PMB. A linear fitting equation was obtained between the quenching efficiency (QE) of A-CDs and variable contents of Enox in the range of 0.8–25.0 μg/mL. And the limit of detection (LOD) was 0.64 μg/mL. The recovery of the injection of Enox in human plasma was acceptable with rational relative standard deviations. Moreover, this fluorescence sensing strategy possesses the prospect of developing reliable pharmaceutical analysis method based on the consideration of drug’s property and pharmacological action and the controllable design of fluorescence probes.
Wei Dong,Xiuhua Wang,Chang Liu,Xiao Zhang,Xin Zhang,Xianzhi Chen,Yongqiang Kou,Shirui Mao
In the present study, chitosan based polymer-lipid hybrid nanoparticles (PLNs) were prepared by a self-assembly method and their use as the carrier for oral absorption enhancement of enoxaparin was evaluated. The enoxaparin-loaded nanoparticles were composed of chitosan as the polymer and glyceryl monooleate as the lipid with a lipid/polymer mass ratio ranging from 0 to 0.3, and F127 was added as a stabilizer. It was found that the PLNs showed a higher surface hydrophobicity but mucoadhesive properties similar to those of chitosan based nanocomplexes. Results from DSC experiments and NMR solvent relaxation study indicate that glyceryl monooleate was completely incorporated into the nanoparticles and the lipid/polymer ratio affected the extent of lipid-polymer interaction inside the nanoparticles and the resultant internal structures. The stability of the PLNs in simulated gastrointestinal fluids was also affected by the lipid/polymer ratio; the best stability was shown by nanoparticles with a lipid/polymer ratio of 0.2. Nanoparticles with the optimal composition significantly enhanced the oral bioavailability of enoxaparin with a 4.5-fold increase in AUC in comparison with a solution of enoxaparin. In conclusion, GMO/CS based PLNs can provide a new insight to develop orally applicable delivery system for hydrophilic macromolecules. Their absorption can be enhanced with proposed PLNs and preparation of this PLNs was also found to be easy comparing to other similar methods.
Fanqi Kong,Hongyue Yu,Lifei Gao,Enyun Xing,Yan Yu,Xiaofei Sun,Wenxing Wang,Dongyuan Zhao,Xiaomin Li
A persistent inflammatory response, intrinsic limitations in axonal regenerative capacity, and widespread presence of extrinsic axonal inhibitors impede the restoration of motor function after a spinal cord injury (SCI). A versatile treatment platform is urgently needed to address diverse clinical manifestations of SCI. Herein, we present a multifunctional nanoplatform with anisotropic bimodal mesopores for effective neural circuit reconstruction after SCI. The hierarchical nanoplatform features of a Janus structure consist of dual compartments of hydrophilic mesoporous silica (mSiO2) and hydrophobic periodic mesoporous organosilica (PMO), each possessing distinct pore sizes of 12 and 3 nm, respectively. Unlike traditional hierarchical mesoporous nanomaterials with dual-mesopores interlaced with each other, the two sets of mesopores in this Janus nanoplatform are spatially independent and possess completely distinct chemical properties. The Janus mesopores facilitate controllable codelivery of dual drugs with distinct properties: the hydrophilic macromolecular enoxaparin (ENO) and the hydrophobic small molecular paclitaxel (PTX). Anchoring with CeO2, the resulting mSiO2&PMO-CeO2–PTX&ENO nanoformulation not only effectively alleviates ROS-induced neuronal apoptosis but also enhances microtubule stability to promote intrinsic axonal regeneration and facilitates axonal extension by diminishing the inhibitory effect of extracellular chondroitin sulfate proteoglycans. We believe that this functional dual-mesoporous nanoplatform holds significant potential for combination therapy in treating severe multifaceted diseases.
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