Commercial hydrogels for biomedical applications.

https://digital.csic.es/bitstream/10261/170982/4/freeze-surimi.pdf

Freeze-dried phosphatidylcholine liposomes encapsulating various antioxidant extracts from natural waste as functional ingredients in surimi gels.

The blood–brain barrier (BBB) is a barrier that separates the blood from the brain tissue and possesses unique characteristics that make the delivery of drugs to the brain a great challenge. To achieve this purpose, it is necessary to design strategies to allow BBB passage, in order to reach the brain and target the desired anatomic region. The use of nanomedicine has great potential to overcome this problem, since one can modify nanoparticles with strategic molecules that can interact with the BBB and induce uptake through the brain endothelial cells and consequently reach the brain tissue. This review addresses the potential of nanomedicines to treat neurological diseases by using nanoparticles specially developed to cross the BBB.

Nanoparticles for Targeted Brain Drug Delivery: What Do We Know?

Tetramethylpyrazine: A review on its mechanisms and functions.

This review aims to study the properties of bio-nanocomposite polymer hydrogels containing nanoparticles and their application in drug delivery systems. Several biopolymer hydrogel nanoparticulate systems have been prepared and characterized in recent years, based on both natural and synthetic biopolymers, each with its own advantages and drawbacks. Among the natural biopolymers, cellulose, carboxymethyl cellulose, chitosan, carboxymethyl chitosan, alginate, starch, and gelatin have been studied extensively for preparation of bio-nanocomposite hydrogels, and from synthetic group, bio-nanocomposite hydrogels based on poly (vinyl alcohol) and poly (ethylene glycol) have been reported with various properties with respect to drug delivery. Bio-nanocomposite hydrogel has obtained significant attention in recent years as one of the most promising nanoparticulate drug delivery systems owing to their unique potentials by combining the characteristics of a hydrogel system with a nanoparticle. The field of drug delivery has achieved a considerable progress in recent years, especially with the rapid advance of nano-medicine in combination with the growing understandings of infectious and cancer diseases. Hydrogels and inorganic/organic nanoparticles are two distinguished classes of materials that have received significant attention in recent years because of their ideal characteristics in different fields including materials, chemistry, and biological sciences. The application of nanoparticles in biopolymer hydrogel matrix and their use in drug delivery field has become increasingly popular with many research groups and industries. The field of drug delivery has achieved a considerable progress in recent years, especially with the rapid advance of nano-medicine in combination with the growing understandings of infectious and cancer diseases.

Bio-nanocomposite Polymer Hydrogels Containing Nanoparticles for Drug Delivery: a Review

Tetramethylpyrazine-loaded poloxamer hydrogel materials were studied to achieve the controlled release of tetramethylpyrazine. First, hydrogels having different concentrations of poloxamer 407 and poloxamer 188 were prepared. The gelling temperature and viscosity were measured. Second, we investigated the tetramethylpyrazine release rate from the thermosensitive poloxamer hydrogel materials in vitro and ex vivo. Finally, further study of the pharmacological efficacy of the tetramethylpyrazine-loaded thermosensitive poloxamer hydrogel materials was also investigated in vivo. The in vitro, ex vivo and in vivo experimental results showed that the tetramethylpyrazine-loaded poloxamer hydrogel with the appropriate gelling temperature, good adhesion and easy preparation controlled the release of tetramethylpyrazine. The hydrogel with the suitable nasal temperature and a satisfactory adhesion was selected. The relevant tests were carried out, including the determination of the concentration of drugs in the brain homogenate and the anti-inflammatory test after different modes of administration. So the poloxamer hydrogel was a novel carrier to deliver TMP to pass across the blood brain barrier via nasal administration.

The Controlled Release and Anti-Inflammatory Activity of a Tetramethylpyrazine-Loaded Thermosensitive Poloxamer Hydrogel

Investigating the passage of tetramethylpyrazine-loaded liposomes across blood-brain barrier models in vitro and ex vivo

The purpose of this study was to prepare and evaluate kaempferol-loaded carbopol polymer (acrylic acid) hydrogel, investigate its antioxidant activity in vitro, and compare the effects on drug release under different pH conditions. Drug release studies were conducted in three different pH media (pH 3.4, 5.4, and 7.4). The kaempferol-loaded hydrogel was prepared by using carbopol 934 as the hydrogel matrix. The morphology and viscosity of the preparation were tested to understand the fluidity of the hydrogel. The antioxidant activity of the preparation was studied by scavenging hydrogen peroxide and 2,2-diphenyl-1-picrilhidrazil (DPPH) radicals in vitro and inhibiting the production of malondialdehyde in mouse tissues. The results showed that kaempferol and its preparations had high antioxidant activity. In vitro release studies showed that the drug release at pH 3.4, 5.4, and 7.4 was 27.32 ± 3.49%, 70.89 ± 8.91%, and 87.9 ± 10.13%, respectively. Kaempferol-loaded carbopol hydrogel displayed greater swelling and drug release at higher pH values (pH 7.4).

/pdf/in-vitro-evaluation-of-kaempferol-loaded-hydrogel-as-ph-23ej6s1l.pdf

In Vitro Evaluation of Kaempferol-Loaded Hydrogel as pH-Sensitive Drug Delivery Systems

Tetramethylpyrazine (TMP) was extracted from Ligusticum chuanxiong hort. The compound is known to have a variety of medicinal functions; in particular, it is used for the treatment of cerebral ischemic diseases. TMP-loaded hydrogels offer an excellent preparation with the capacity to bypass the blood-brain barrier, allowing treatment of the brain through intranasal administration. We prepared TMP-loaded hydrogels using carbomer 940 and evaluated the release of TMP from the hydrogel. We determined the release rate using Franz-type diffusion cell experiments with a subcutaneous-mucous-membrane model and also by a molecular dynamics (MD) simulation. In general, the former method was more complicated than the latter was. The dynamic behavior of TMP release from the hydrogel was revealed by analysis of the mean square displacement of the trajectory in the MD simulation. The coefficient of TMP diffusion from the hydrogel was calculated at different temperatures (277, 298, and 310 K) by using MD software. The results showed that the coefficient of diffusion increased with an increase in temperature. This trend was observed both experimentally and in the MD simulation. Therefore, the MD simulation was a complementary method to verify the experimental data.

Tetramethylpyrazine-Loaded Hydrogels: Preparation, Penetration Through a Subcutaneous-Mucous-Membrane Model, and a Molecular Dynamics Simulation.

Retinoic acid (RA), a metabolite of retinol, is one of the most biologically active forms of retinoid and plays vital roles in embryonic development and in the regulation of cell proliferation and differentiation. Knowing that liposomes simulate cell membranes and that hydrogel is an ideal delivery vehicle for topical medicine, liposome-hydrogel is a novel preparation that has synergistic advantages over each component separately. Our objective was to investigate the characteristics of RA liposome-hydrogel. For quality control of the RA-loaded liposomes, we measured their morphology, particle size, Zeta-potential, and entrapment efficiency. Then we determined the viscosity of RA liposome-hydrogel. Next, the diffusion through mouse skin was explored, followed by investigation of the mRNA expression levels of Ker18, REX1, and α-FP using Q-PCR. The results showed that RA liposome-hydrogel penetrates the mouse skin effectively. The permeation rates were: Qn (%) of RA liposome-hydrogel < Qn(%) of RA-loaded liposome < Qn (%) of RA. The mRNA expression levels were dose-dependent and the effective dose decreased between vehicles due to their different release rates. F9 mouse teratocarcinoma stem cells were an ideal model to explore the mechanism of RA liposome-hydrogel in stem cell differentiation.

/pdf/retinoic-acid-liposome-hydrogel-preparation-penetration-9b7zogk63a.pdf

Yongfeng Cheng

Papers

The Controlled Release and Anti-Inflammatory Activity of a Tetramethylpyrazine-Loaded Thermosensitive Poloxamer Hydrogel

Investigating the passage of tetramethylpyrazine-loaded liposomes across blood-brain barrier models in vitro and ex vivo

In Vitro Evaluation of Kaempferol-Loaded Hydrogel as pH-Sensitive Drug Delivery Systems

Tetramethylpyrazine-Loaded Hydrogels: Preparation, Penetration Through a Subcutaneous-Mucous-Membrane Model, and a Molecular Dynamics Simulation.

Retinoic acid liposome-hydrogel: preparation, penetration through mouse skin and induction of F9 mouse teratocarcinoma stem cells differentiation