Drug delivery systems (DDS) in the form of nanometric or micrometric objects in which active pharmaceutical ingredients (APIs) are encapsulated are engineered to provide accurate tissue targeting to minimize systemic exposure[1]. We developed poly(sebacic acid)-based DDS of antibiotics (gentamycin, tobramycin, azithromycin) and quorum sensing inhibitors (curcumin, linolenic acid) for the treatment of bacterial infections in patients with chronic obstructive pulmonary disease (COPD) exacerbations. Such DDS have a suitable size for inhalation (aerodynamic diameter in the range of 1-5 µm), degrade in a few days and release APIs cargo, which is capable of killing bacteria causing COPD and preventing biofilm formation[2]. The developed DDS are cytocompatible with lung epithelial cells, as shown by in vitro and ex vivo tests[3]. We developed poly(L-lactide-co-glycolide) carriers of antibiotics to treat osteomyelitis and infected bone tissue lesions. By adjusting manufacturing conditions during emulsification, we control the size of the particles from 100 nm to 10 µm range. Furthermore, by modification of antibiotic molecules to make them more hydrophobic and thus compatible with the polymeric matrix, we can achieve API encapsulation efficiency up to 99%[4]. The particles can be suspended in biocompatible hydrogels of natural or synthetic origin, to better control the doses released and prevent spreading the particles to distant places in the body. They can also be immobilised on the pore walls of highly porous ceramic scaffolds, thus providing them with mechanical support and antibacterial properties[5]. Therefore, our DDSs can be useful in the treatment of persistent infections in the lungs and bone tissue.

Pullulan is a polysaccharide with significant potential as a drug delivery vehicle in the pharmaceutical field. It is biodegradable, biocompatible, and derived from a green process, commonly using sugarcane bagasse. Its high-water solubility enables a non-organic-solvent process, reducing the toxicity of the final drug-release vehicle. However, pullulan requires modification to reduce its water solubility for sustained and controlled drug release.
This study focuses on developing and optimizing pullulan-based hydrogels for tuberculosis treatment. Pullulan was modified with methacrylic anhydride (MA) to enable UV-induced crosslinking in the presence of a photoinitiator [1–3]. MA concentrations (0.5%, 1.5%, and 3.0%) influenced the degree of pullulan modification, verified by FTIR and H-NMR analyses. UV exposure duration was optimized using a rheometer to ensure stable viscosity, indicating complete crosslinking. Hydrogels were characterized using DSC and swelling capacity tests.
The hydrogels were employed as drug delivery systems for isoniazid (INH), a first-line treatment for all forms of tuberculosis. In vitro release studies, simulating gastrointestinal conditions, evaluated isoniazid (INH) release profiles. The influence of crosslinking degree on drug release kinetics was analyzed. This study demonstrates the potential of pullulan-based hydrogels as green, customizable materials for sustainable drug delivery. These findings highlight their application in enhancing tuberculosis treatment and addressing global health challenges.

Poly(2-alkyl-2-oxazoline)s (POx) have been attracting attention of researchers due to their possibility to combine biocompatibility with stealth behavior, making them ideal candidates for use in a wide variety of biomedical applications [1, 2, 3].
In this presentation we will underline the chemical tools for the design of poly(2-oxazoline)s based Drug Delivery Systems (DDS).
Specifically, we will present a greener synthetic approach that gives a simple and more environmentally friendly route to synthesizing gold nanoparticles (AuNPs) for biomedical applications. In this study, we detail a novel one-step, green synthesis of POx-coated AuNPs, which eliminates the need for additional reducing and stabilizing agents and the potential of NPs against aggressive brain tumour [3].
We will show possibility to modulate the interaction of the POx-micelles with tumor cells.
Finally, we will underscore the potential of heavy-atom-free photosensitizer (HAF-PS) loaded lipid nanocapsules (LNC) PEG-LNC/ POx-LNC as highly efficient, targeted nanocarriers for photodynamic therapy (PDT), as safer and effective cancer therapies with minimization of side effects [4].

Hydrogels, 3D cross-linked polymeric networks, have diverse biomedical applications, particularly in drug delivery. Incorporating nanoparticles (NPs) into hydrogels can enhance therapeutic effects by enabling more targeted and sustained release. Biomimetic NPs (BNPs), which integrate leukocyte membrane proteins and were developed by Dr. Assaf Zinger's group, offer significant potential for therapeutic outcomes. However, due to their nanometric size, the controlled release of these BNPs from the hydrogel network cannot occur via a diffusion mechanism.
This study aims to develop an interpenetrating polymer network (IPN) hydrogel platform for the controlled release of novel BNPs. The hydrogel dissolves at physiological conditions, allowing the BNPs to release and evaluate its therapeutic effects. We focus on creating a physically cross-linked IPN hydrogel using konjac glucomannan (KGM) and kappa-carrageenan (KCAR) polysaccharides, with embedded BNPs. The study investigates the physical, mechanical, and rheological properties of the hydrogels, including their ability to release BNPs at a controlled rate. We also assess the therapeutic effects of this release in in vitro inflammation models.
Preliminary results demonstrate the successful fabrication of KGM-KCAR hydrogels incorporating BNPs. The hydrogels exhibited self-healing and shear-thinning properties, with tunable dissolution and BNP release rates, influenced by potassium chloride (KCl) as a physical cross-linker. Additionally, the formulation reduced TNF-alpha cytokine levels in an in vitro inflammation model, without significantly affecting cell viability. This research suggests that the KGM-KCAR hydrogel platform offers a promising approach for controlled release of BNPs, providing therapeutic potential in various medical applications.

Hybrid hydrogels combining natural and synthetic polymers have recently gained attention in the biomedical field for their ability to form materials with well-defined structures and bioactive properties. [1] The integration of synthetic polymers like poly(N-isopropylacrylamide) (PNIPAM) with natural biomolecules such as keratin unites the thermo-responsive behavior of PNIPAM with the bioactivity of keratin [2]. PNIPAM is widely used due to its lower critical solution temperature of approximately 32°C, close to human body temperature. Keratin, on the other hand, offers intrinsic bioactive features, including the promotion of cell adhesion, proliferation, and differentiation.
In this study, we exploit keratin derived from wool waste in the textile industry, extracted via sulfitolysis [3], to synthesize hybrids with PNIPAM microgel. Utilizing two distinct methods— polymerization of NIPAM with keratin (HYB-P) and mixing preformed PNIPAM microgels with keratin (HYB-M)—resulted in hybrids with 20% and 25% keratin content, respectively. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed the formation of colloidal systems, while spectroscopic (FTIR and NMR) and elemental analyses identified a grafted structure for HYB-P particles. To explore their potential as novel delivery systems, caffeic acid was used as a model drug. The impact of encapsulation on size distribution was analyzed by DLS, with drug entrapment efficiency and release profiles evaluated via UV-Vis spectroscopy. Additionally, thin films were prepared from the microgel dispersions by solvent casting. The cytocompatibility of the samples was assessed using immortalized keratinocyte cells (HaCaT), showing promising results from the synergic combination of PNIPAM and keratin.

pH-sensitive degradable hydrogels are smart materials that can cleave covalent bonds upon pH variation, leading to their degradation.[1,2] Their development led to many applications for drug delivery, where drugs can be released in a pH-dependent manner.[3] Crosslinking hyperbranched polyglycerol (HPG), a biocompatible building block bearing high end-group functionality, using oxalic acid (OA), a diacid that can be synthesized from CO₂ and form highly activated ester bonds, can generate this type of smart hydrogel. Aiming to understand the process of developing this novel material and its drug release for oral administration, its formation was studied by varying reactant stoichiometry, concentration and cure procedure and temperature; it was characterized regarding gel percent (%gel), swelling degree (%S), Fourier Transformed Infrared Spectroscopy (FTIR) and thermal behavior; impregnated using ibuprofen, as a model drug, and a release study was carried out at pH 2 and 7. Hydrogel formation was evidenced by its insolubility, FTIR spectra and an increase in thermal degradation and glass transition temperatures; a pre-cure step was shown to be crucial for its formation and an increase in the concentration of the reactants led to higher %gel and lower %S. The impregnation resulted in a matrix-encapsulated system; and the ibuprofen release was negligible at pH 2 but completed at pH 7 due to the hydrolysis of the matrix.[4] A pH-sensitive degradable HPG-OA hydrogel was obtained and it can largely be beneficial in controlled drug release applications.