Fibrous Clays in Dermopharmaceutical and Cosmetic Applications: Traditional and Emerging Perspectives

Characterization of percutaneous absorption of calcium, magnesium, and potentially toxic elements in two tailored sulfurous therapeutic peloids: a comprehensive in vitro pilot study

Pelotherapy treatments in thermal spas, which utilize peloids composed of clay minerals mixed with saltwater or mineral-medicinal water, can have various effects on spa users, ranging from therapeutic to potential adverse reactions. Despite the widespread use of peloids, comprehensive information on the penetration and permeation of essential and potentially toxic elements into deeper layers of the skin during pelotherapy is limited. Understanding the concentrations of these elements is crucial for evaluating therapeutic benefits and ensuring safety. This study investigates the in vitro availability and absorption of calcium, magnesium, and potentially toxic elements in two peloids, considering their formulation matrix. To replicate the pelotherapy methodology, an in vitro permeation experiment was conducted using a vertical diffusion chamber (Franz cells) and a biological system with human skin membranes from five Caucasian women, age range between 25 and 51 years. The experiment involved heating the peloids to 45℃. The results emphasize the possible transport properties of chemical elements in peloids, providing valuable information related to potential therapeutic efficacy and safety considerations. Despite no apparent differences between peloids' chemical composition, the method identified permeation variations among chemical elements. The methodology employed in this study adheres to the guidelines outlined by OECD for analyzing skin absorption through an in vitro approach. Furthermore, it aligns with the associated OECD guidance document for conducting skin absorption studies. The replicability of this methodology not only facilitates the analysis of peloids pre-formulation but also provides a robust means to evaluate the effectiveness of therapeutic elements during topical administration, particularly those with potential toxicity concerns.

Room-temperature fabrication of fluorinated covalent organic polymer @ Attapulgite composite for in-syringe membrane solid-phase extraction and analysis of domoic acid in aquatic products

A novel fluorinated covalent organic polymer @ attapulgite composite (F-COP@ATP) was prepared at room temperature for in-syringe membrane solid-phase extraction (SM-SPE) of domoic acid (DA) in aquatic products. Natural ore ATP has the advantages of low cost, good mechanical strength and abundant hydroxyl group on its surface, and in-situ modified F-COP layer can provide abundant adsorption sites. F-COP@ATP combining the advantages of F-COP and ATP, becomes an ideal adsorbent for DA extracting. Moreover, a high-throughput sample preparation strategy was carried out by using the F-COP@ATP membrane as syringe filter and assembling syringes with a ten-channel injection pump. In addition, the experimental factors were optimized, such as pH of extract, amount of adsorbent, velocity of extraction and desorption, type and volume of desorption solvent. The DA analytical method was established by SM-SPE-HPLC/tandem mass spectrometry. The method had a wide linear range with low limit of detection (0.344 ng/kg) and low limit of quantification (1.14 ng/kg). F-COP@ATP membrane can be reused more than five times. The method realized the analysis of DA in scallop and razor clam samples, which shows its application prospect in practical analysis. This study provided an efficient, low-energy and mild idea for preparing other reusable natural mineral ATP-based composite materials for separation and enrichment, which reduces the experimental cost and is closer to environmental protection and green chemistry to a certain extent.

Bio-clay: Antioxidant-rich and stable for body mud scrubs

Clay is naturally occurring and poses a low risk. It is distinguished by mineral composition and ability to adsorb plant colorants and phytochemicals effectively. This study aimed to enhance the stability of bio-clay by preparing body mud scrubs through a solid-state reaction, combining volcanic clay with herbal plants, including Bougainvillea spp., Pandanus amaryllifolius Roxb., and Curcuma longa L. (bio-clay). The characterization of purification clay revealed strong stability within its mineral composition. The optimum condition for sampling was 4 °C, which reserved the total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. A high Trolox equivalent antioxidant capacity (TEAC; mg TEAC/g sample) and low half-maximal inhibitory concentration (IC50) indicated excellent antioxidant activity. Over a storage period of 28 d, the Bougainvillea spp., Curcuma longa L., purified clay + Bougainvillea spp., and purified clay + Curcuma longa L. samples retained their stability. Their TPC, % scavenging, TEAC, and IC50 showed dominant antioxidant activity, stable active phenolic compounds, and the maintenance of extensive amounts. This compound is widely applied as a unique cosmetic ingredient.

Pullulan nanofibrous films incorporated with W/O emulsions via microfluidic solution blow spinning technology

In this work, pullulan (PUL) nanofibrous films incorporated with water-in-oil emulsions (PE) were prepared by microfluidic blowing spinning (MBS). The microstructures of nanofibers were characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR), and X-ray diffraction (XRD). With the addition of W/O emulsions, the thermal stability, mechanical, and water barrier properties of PUL nanofibers were improved. Increases in emulsion content significantly affected the antioxidant and antimicrobial properties of nanofibrous films. ABTS and DPPH free radical scavenging rates increased from 10.26 % and 8.57 % to 60.66 % and 57.54 %, respectively. The inhibition zone of PE nanofibers against E. coli and S. aureus increased from 11.00 to 20.00 and from 15.67 to 21.17 mm, respectively. In addition, we investigated the freshness effectiveness of PE nanofibrous films on fresh-cut apples. PE nanofibrous films significantly maintained the firmness, and reduced the weight loss and browning index of the fresh-cut apple, throughout the 4 days of storage. Thus, the PE nanofibrous films exhibited good potential to prolong the shelf life of fresh-cut fruit and promote the development of active food packaging.

Recent advances in the application of clay-containing hydrogels for hemostasis and wound healing

INTRODUCTION

Immediate control of bleeding and anti-infection play important roles in wound management. Multiple organ dysfunction syndrome and death may occur if persistent bleeding, hemodynamic instability, and hypoxemia are not addressed. The combination of clay and hydrogel provides a new outlet for wound hemostasis. In this review, the current research progress of hydrogel/clay composite hemostatic agents was reviewed.

AREAS COVERED

This paper summarizes the characteristics of several kinds of clay including kaolinite, montmorillonite, laponite, sepiolite, and palygorskite. The advantages and disadvantages of its application in hemostasis were also summarized. Future directions for the application of hydrogel/clay composite hemostatic agents are presented.

EXPERT OPINION

Clay can activate the endogenous hemostatic pathway by increasing blood cell concentration and promoting plasma absorption to accelerate the hemostasis. Clay is antimicrobial due to the slow release of metal ions and has a rich surface charge with a high affinity for proteins and cells to promote tissue repair. Hydrogels have some properties such as good biocompatibility, strong adhesion, high stretchability, and good self-healing. Despite promising advances, hydrogel/clay composite hemostasis remains a limitation. Therefore, more evidence is needed to further elucidate the risk factors and therapeutic effects of hydrogel/clay in hemostasis and wound healing.

Natural and Synthetic Clay Minerals in the Pharmaceutical and Biomedical Fields

Clay minerals are historically among the most used materials with a wide variety of applications. In pharmaceutical and biomedical fields, their healing properties have always been known and used in pelotherapy and therefore attractive for their potential. In recent decades, the research has therefore focused on the systematic investigation of these properties. This review aims to describe the most relevant and recent uses of clays in the pharmaceutical and biomedical field, especially for drug delivery and tissue engineering purposes. Clay minerals, which are biocompatible and non-toxic materials, can act as carriers for active ingredients while controlling their release and increasing their bioavailability. Moreover, the combination of clays and polymers is useful as it can improve the mechanical and thermal properties of polymers, as well as induce cell adhesion and proliferation. Different types of clays, both of natural (such as montmorillonite and halloysite) and synthetic origin (layered double hydroxides and zeolites), were considered in order to compare them and to assess their advantages and different uses.

Pickering emulsion technology based on the concept of “the combination of medicine and adjuvant” to enhance the oxidation stability of volatile oils in solid preparations—taking Lingzhu Pulvis as an example

The antioxidant properties of the volatile oil of Acorus calamus in Lingzhu Pulvis may be enhanced by the introduction of Pickering emulsion technology based on the concept of “the combination of medicine and adjuvant”. The characterization of each drinking tablet of Lingzhu Pulvis was conducted to determine the stabilizer. The optimal stabilizer concentration, oil–water ratio and preparation method of the Pickering emulsion were then determined and analyzed using NIR. The contents of malondialdehyde and peroxide in the volatile oils of each group were compared at different AIBA concentrations. The trends of the components were then analyzed by GC-MS. The pearl powder was screened as the stabilizer of the Pickering emulsion; the pearl powder concentration of 0.065 g mL⁻¹ and the oil–water ratio of 9 : 11 were found to be the optimal emulsion formation conditions, and the high-pressure homogenization method was the optimal preparation method. The NIR analysis showed that the volatile oil was wrapped by the pearl powder and no new chemical structure formed in the Pickering emulsion. The Pickering emulsions had lower oxidation levels than the crude oil groups at AIBA concentrations of 5, 10, and 15 mg mL⁻¹. The results of the GC-MS analysis showed that the antioxidant properties of the volatile components were significantly higher in the Pickering emulsion group compared to the crude oil group. Pickering emulsions can be used to enhance the antioxidant properties of volatile components in oil-containing solid formulations based on the concept of “the combination of medicine and adjuvant”.

The antioxidant properties of the volatile oil of Acorus calamus in Lingzhu Pulvis may be enhanced by the introduction of Pickering emulsion technology based on the concept of “the combination of medicine and adjuvant”.