Investigation on Swelling of Agar-Based Antibacterial Hydrogels for Hard-To-Heal Wound Dressings.

Despite a wide range of available wound treatments, hard-to-heal wounds still pose a challenge. Hydrogels are often used as dressings for these wounds, because they sustain moisture in the wound environment, supporting the natural healing process. However, it is still not fully understood how physicochemical properties of hydrogel matrix affect the drug release process. Thus, detailed swelling kinetics examination coupled with modeling is needed together with studies on drug release. In this regard, several hydrogels based on plant-derived agar and modified with amikacin were investigated. The main properties of hydrogels were examined focusing on detailed swelling kinetics. Drug release was studied as microbiological activity against E. coli and S. Epidermidis strains. The obtained hydrogels were characterized by high swelling, reaching values in range from 465 to 1300%, fitting the second order kinetics mode and exhibiting the quasi-Fickian diffusion properties. Furthermore, there was no correlation found between swelling properties and antibacterial activity against tested strains. The results confirmed that presented hydrogel materials have desirable properties for application as dressings for hard-to-heal wounds. The suggested compositions are a promising base for modification with other active substances (e.g., regenerative, anti-inflammatory) and studying the broader correlation between swelling and drug release.

Recent advances in 3D bioprinted tumor models for personalized medicine.

Cancerous tumors are among the most fatal diseases worldwide, claiming nearly 10 million lives in 2020. Due to their complex and dynamic nature, modeling tumors accurately is a challenging task. Current models suffer from inadequate translation between in vitro and in vivo results, primarily due to the isotropic nature of tumors and their microenvironment's relationship. To address these limitations, hydrogel-based 3D bioprinting is emerging as a promising approach to mimic cancer development and behavior. It provides precise control over individual elements' size and distribution within the cancer microenvironment and enables the use of patient-derived tumor cells, rather than commercial lines. Consequently, hydrogel bioprinting is expected to become a state-of-the-art technique for cancer research. This manuscript presents an overview of cancer statistics, current modeling methods, and their limitations. Additionally, we highlight the significance of bioprinting, its applications in cancer modeling, and the importance of hydrogel selection. We further explore the current state of creating models for the five deadliest cancers using 3D bioprinting. Finally, we discuss current trends and future perspectives on the clinical use of cancer modeling using hydrogel bioprinting.

Polyurethane based hybrid ciprofloxacin-releasing wound dressings designed for skin engineering purpose.

PURPOSE: Even in the 21st century, chronic wounds still pose a major challenge due to potentially inappropriate treatment options, so the latest wound dressings are hybrid systems that enable clinical management, such as a hybrid of hydrogels, antibiotics and polymers. These wound dressings are mainly used for chronic and complex wounds, which can easily be infected by bacteria. MATERIALS AND METHODS: Six Composite Porous Matrices (CPMs) based on polyurethane (PUR) in alliance with polylactide (PLAs) and poly(vinyl alcohol) (PVA) were prepared and analyzed using optical microscopy. Three different types of hydrogels and their Ciprofloxacin (Cipro) modified variants' ratios were prepared and analyzed using FTIR, SEM and EDX techniques. Six Hybrid Cipro-Releasing Hydrogel Wound Dressings (H-CRWDs) were also prepared and underwent short-term degradation, Cipro release, microbiology and cell viability measurements. RESULTS: Average porosity of CPMs was in the range of 69-81%. The pore size of the obtained CPMs was optimal for skin regeneration. Short-term degradation studies revealed degradability in physiological conditions regardless of sample type. A meaningful release was also observed even in short time (21.76 â€‹± â€‹0.64 â€‹µg/mL after 15 â€‹min). Microbiological tests showed visible inhibition zones. Cell viability tests proved that the obtained H-CRWDs were biocompatible (over 85% of cells). CONCLUSIONS: A promising hybrid wound dressing was labeled. Simple and cost-effective methods were used to obtain microbiologically active and biocompatible dressings. The results were of importance for the design and development of acceptable solutions in the management of chronic wounds of high potential for infection.