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The mechanical performance of three-dimensional (3D) bioprinted scaffolds is susceptible to printing parameters and material formulation. In this study, poly ( ε -caprolactone) (PCL) scaffolds were fabricated using four different polymer concentrations (10%, 25%, 50%, and 75% w/v) to investigate how these variations, along with process parameters, influence mechanical behavior. Maintaining the structural integrity of bioprinted constructs requires careful optimization of polymer concentration and precise control over parameters such as printing speed, pressure, and infill density. Tensile tests were conducted to evaluate the effects of these variables. Among the tested conditions, a 50% (w/v) concentration allowed for a broader operational window, enabling fabrication across a range of printing speeds and pressures. At a printing speed of 5 mm s −1 , PCL-DCM exhibited a Young’s modulus of 39.0 MPa, while PCL-CF samples printed at 10 mm s −1 achieved the highest modulus of 32.0 MPa. Notably, when the printing speed was kept constant, applying higher pressures led to an increase in Young’s modulus, suggesting that pressure plays a key role in enhancing scaffold stiffness. When comparing the 50% and 75% (w/v) polymer concentrations, the 50% (w/v) formulation stood out by offering both higher elongation and greater stiffness, which makes it particularly suitable for load-bearing applications. These findings provide a quantitative framework for optimizing extrusion-based bioprinting of PCL scaffolds, with implications for customized biomedical implants and regenerative medicine.

This study aims to prepare a novel breast cancer-targeted micelle-based nanocarrier, which is stable in circulation, allowing intracellular drug release, and to investigate its cytotoxicity, apoptosis, and cytostatic effects, in vitro. The shell part of the micelle is composed of zwitterionic sulfobetaine ((N-3-sulfopropyl-N,N-dimethylamonium)ethyl methacrylate), while the core part is formed by another block, consisting of AEMA (2-aminoethyl methacrylamide), DEGMA (di(ethylene glycol) methyl ether methacrylate), and a vinyl-functionalized, acid-sensitive cross-linker. Following this, a targeting agent (peptide (LTVSPWY) and antibody (Herceptin®)), in varying amounts, were coupled to the micelles, and they were characterized by 1H NMR, FTIR (Fourier-transform infrared spectroscopy), Zetasizer, BCA protein assay, and fluorescence spectrophotometer. The cytotoxic, cytostatic, apoptotic, and genotoxic effects of doxorubicin-loaded micelles were investigated on SKBR-3 (human epidermal growth factor receptor 2 (HER2)-positive) and MCF10-A (HER2-negative). According to the results, peptide-carrying micelles showed a higher targeting efficiency and better cytostatic, apoptotic, and genotoxic activities than antibody-carrying and non-targeted micelles. Also, micelles masked the toxicity of naked DOX on healthy cells. In conclusion, this nanocarrier system has great potential to be used in different drug-targeting strategies, by changing targeting agents and drugs.

To achieve high stability and biocompatibility in physiological environment, oligoethyleneglycol methacrylate (OEGMA) and 4-vinylpyridine (4VP)-based amphiphilic block copolymers were prepared as micellar carriers to deliver doxorubicin into tumor cells. First, macroinitiator of OEGMA was synthesized by RAFT polymerization at [M] 0 /[CTA] 0 /[I] 0 ratio of 100/1/0.2 in dimethylformamide (DMF) at 70 °C, in the presence of 4,4′-azobis(4-cyanovaleric acid) (ACVA) as initiator and 4-cyano-4-(thiobenzoylthio)pentanoic acid (CTA) as chain transfer agent, respectively. It was followed by copolymerization with 4-VP at similar conditions. The formation of RAFT-mediated polymers was approved by FTIR, 1 H-NMR and GPC. For the preparation of drug-loaded micelles, a dialysis method was applied and hydrophobic doxorubicin, as a model drug, was entrapped into the micelles. Size distributions and morphologies of drug-loaded micelles were investigated by light scattering and scanning electron microscopy, respectively. Critical micelle concentration was estimated as 0.0019 mg/mL by measuring light scattering intensity in different polymer concentrations. Also, drug loading and entrapment efficiencies were calculated as 4.41% and 17.65% by measuring the DOX amount in the micelles, spectrophotometrically. At last, the drug-loaded micelles were applied to SKBR-3 breast cancer cell lines and revealed up to %40 cell inhibition at 48 and 72 h. As a result, these nanosized and biocompatible micelles can be used for the delivery of hydrophobic drugs, and they can also be modified for further targeting and imaging applications toward specific cancer cells. Graphical abstract

Innovative and bioactive wound dressings prepared by electrospinning mimicking the native structure of the extracellular matrix (ECM) have gained significant interest as an alternative to conventional wound care applications. In this study, bilayered wound dressing material was produced by sequential electrospinning of quaternized poly(4-vinyl pyridine) (upper layer) on the Centella Asiatica (CA) extract containing electrospun poly(D, L-lactide-co-glycolide) (PLGA)/poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PHBV) blend membrane (lower layer). Scanning electron microscopy (SEM) was utilized to show a uniform and bead-free fiber structure of electrospun membranes. The average diameter of CA extract containing electrospun PLGA/PHBV blend membrane was calculated 0.471±0.11 µm, whereas the average fiber diameter of electrospun poly(Q-VP) membranes was in the range of 0.460±0.057 µm. Chemical, thermal, mechanical properties, and adsorption capacity of electrospun membranes, as well as the cumulative release of CA from the electrospun PLGA/PHBV membrane, were investigated. Viability, adhesion, and attachment of human fibroblast cells on the electrospun membranes on pre-set days were evaluated by the colorimetric CellTiter 96® Aqueous One Solution Cell Proliferation Assay (MTS assay) and SEM. Results revealed that CA loaded bilayered electrospun wound dressing showed promoted attachment and proliferation of fibroblasts. Hence, it can be concluded that CA extract containing bilayered electrospun wound dressing prepared in this study has a promising potential for wound healing applications.

This study aims to prepare a novel breast cancer-targeted micelle-based nanocarrier, which is stable in circulation, allowing intracellular drug release, and to investigate its cytotoxicity, apoptosis, and cytostatic effects, in vitro. The shell part of the micelle is composed of zwitterionic sulfobetaine ((N-3-sulfopropyl-N,N-dimethylamonium)ethyl methacrylate), while the core part is formed by another block, consisting of AEMA (2-aminoethyl methacrylamide), DEGMA (di(ethylene glycol) methyl ether methacrylate), and a vinyl-functionalized, acid-sensitive cross-linker. Following this, a targeting agent (peptide (LTVSPWY) and antibody (Herceptin[sup.®] )), in varying amounts, were coupled to the micelles, and they were characterized by [sup.1] H NMR, FTIR (Fourier-transform infrared spectroscopy), Zetasizer, BCA protein assay, and fluorescence spectrophotometer. The cytotoxic, cytostatic, apoptotic, and genotoxic effects of doxorubicin-loaded micelles were investigated on SKBR-3 (human epidermal growth factor receptor 2 (HER2)-positive) and MCF10-A (HER2-negative). According to the results, peptide-carrying micelles showed a higher targeting efficiency and better cytostatic, apoptotic, and genotoxic activities than antibody-carrying and non-targeted micelles. Also, micelles masked the toxicity of naked DOX on healthy cells. In conclusion, this nanocarrier system has great potential to be used in different drug-targeting strategies, by changing targeting agents and drugs.

Herein, we fabricated polycaprolactone/gelatin electrospun membranes possessing different amounts of Viburnum Opulus  extract (0, 25, 35, 50%, w/v) as an antibacterial wound dressing. We investigated chemical, morphological, physical, and mechanical properties as well as in vitro degradation behavior of the electrospun membranes. The antibacterial activities of membranes were evaluated against gram-positive  Staphylococcus aureus (S. aureus)  and gram-negative Escherichia coli (E. coli) . The membranes containing  Viburnum Opulus  exhibited excellent antibacterial activity with the formation of inhibition zones of 25 mm to 36 mm against  Escherichia coli  and 14 mm to 25 mm against  Staphylococcus aureus . The fiber diameters rose from 591 to 1222 nm after adding Viburnum Opulus  extract. The extract-containing membranes displayed superior swelling, cell viability, and proliferation properties to neat membranes. Our results showed that the polycaprolactone/gelatin electrospun membranes containing Viburnum Opulus  could be a suitable material for wound dressing applications.

We report the synthesis of N -(2-hydroxypropyl)methacrylamide ( HPMA) macroCTA and HPMA- b -4-Vinylpyridine block copolymers via reversible addition-fragmentation chain transfer (RAFT) reaction. Polymerization was carried out in dimethylformamide (DMF) at 70 °C using 4-Cyano-4(thiobenzoylthio) pentanoic acid as chain transfer agent and AIBN as an initiator. Control over molecular weight and composition was achieved by altering the CTA, monomer and initiator feed ratio. The controlled living character of the polymerization was verified with pseudo-first-order kinetic plots, a linear increase of the molecular weight with conversion, and low polydispersities (PDIs ≤ 1.2). Effect of microwave heating on the homo- and copolymer formation was investigated and the rates were significantly higher than those observed under conventional heating conditions. These polymerization reactions were in controlled fashion resulting in polymers with low PDIs, too. These polymers have a great potential to be used in developing delivery vehicles and conjugates for further drug or gene delivery applications.

Biomaterials are widely used in diverse applications as substances, materials or important elements of biomedical devices. Biodegradable polymers, both natural and synthetic, have been utilized in applications in which they act as temporary substitutes. Poly(αα-hydroxy acids), especially lactic acids and glycolic acid and their copolymers with ε-caprolactone, are the most widely known and used among all biodegradable polymers. They degrade into safe end products mainly by hydrolysis in a few weeks to several months, depending on several factors, including molecular structure/morphology, average molecular weight, size and shape. They are processed into tailor-made materials for diverse applications, although mainly for soft and hard tissue repair. Electrospinning is a method of producing nanofibers and nonwoven matrices from their solutions and melts. Several factors affect fiber diameter and resulting nonwoven structures/morphologies. Recently, electrospun matrices made of lactic acids, glycolic acid and ε-caprolactone homo- and co-polymers have been attracting increasing attention for fabrication of novel materials for medical use. This review briefly describes poly(αα-hydroxy acids) and the elecrospinning process, and gives some selected recent applications of electrospun matrices made from these polymers.