Preparation and Drug Release Properties of a Thermo Sensitive GA Hydrogel

Abstract

A high-strength galactomannan (GA)-based hydrogel with thermal response and pH response is introduced in this paper. GA, N-isopropylacrylamide (NIPAM), N-[3-dimethylamino)propyl]methylacrylamide (DMAPMA), and montmorillonite were used to form hydrogels through a simple mixed static system. Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were used to characterize the structure and properties of the hydrogels. The compressive strength of the the hydrogel increased from 23.9 to 105.61 kPa with the increase of GA dosage from 0 to 1.5 wt%. When the NIPAM content in the monomer increased from 75% to 95%, the lower critical solution temperature (LCST) of the hydrogel changed from 36.5 to 45.8 °C. When the monomer content was higher than 10wt%, the swelling kinetics of the sample changed from the second-order equation to the first-order equation. With the increase of the proportion of NIPAM monomer, the release rate of bovine serum album in the early stage was faster, and the cumulative release rate was close to 100%.The release rate of bovine serum albumin at 37 °C was higher than that at 25 °C. The release rate of the hydrogel containing bovine serum albumin was the fastest under the condition of pH 7.4, followed by those at pH 6.6 and pH 5.0. The results showed that this thermal-responsive hydrogel has potential applications as a drug carrier for colon delivery.

Soft/Hard Controllable Conversion Galactomannan Ionic Conductive Hydrogel as a Flexible Sensor

“…When the temperature is higher than the phase-transition temperature, the polymer chain absorbs energy and gathers together, and the hydrogen bond with water is completely broken, resulting in the contraction of the molecular chain and the decrease of water absorption. 41 3.2. Structure of the GA-PNIPAM Hydrogel.…”

“…When the temperature increases gradually, entropy drives the hydrophobic interaction of isopropyl in water, and the hydrophobic force increases continuously. When the temperature is higher than the phase-transition temperature, the polymer chain absorbs energy and gathers together, and the hydrogen bond with water is completely broken, resulting in the contraction of the molecular chain and the decrease of water absorption …”

“…The increase of the ambient temperature has a certain effect on the resistance change rate (Figure e,f). This is because increasing the temperature and prolonging the soaking time will lead to volume shrinkage of the hydrogel, , resulting in compact pores, which will affect ion transport, leading to the increase of the resistance rate.…”

“…TMEDA (72 μL) was added under ice-water bath conditions and stirred for 1 min. The solution was placed in a fixed mold and kept at room temperature for 12 h. , After the hydrogel was prepared, it was soaked in NaCl or sodium borate solution.…”

An injectable thermosensitive hydrogel with a self-assembled peptide coupled with an antimicrobial peptide for enhanced wound healing

“…4C and D, the PNI/RA-Amps3 hydrogel shows a porous structure with an average diameter of 245.7 AE 152.97 mm, with the porous three-dimensional network structure with high water content being conducive to the continuous and partial delivery of drugs from the inside of the hydrogel. [47][48][49] PNIPAM, a temperature-sensitive material, undergoes structural transformation from a ''coil'' to ''globule'' with a change in temperature along with dehydration phenomenon in the phase transformation process. 50,51 As a hydrophilic drug, the MGF E peptide is released by escaping from water during the dehydration phenomenon.…”