Cellulose is a biopolymer of great interest for biomedical applications, providing increased rigidity and strength in polymer matrices, biocompatibility, and non–toxicity. However, the hydrophilic structure of cellulose leads to the aggregation of its particles in hydrophobic matrices. The presence of OH groups in the cellulose structure opens up wide possibilities for its chemical modification in order to improve compatibility. Most cellulose modification processes involve expensive toxic solvents, which helps to reduce the environmental friendliness of the process.

Graft copolymerization of cellulose and polyester resin based on sebacic acid was carried out by the method of mechanochemical activation, and a compatibilizer was obtained. The IR spectroscopy method shows the grafting of polyester to cellulose and selects the optimal amount of polyester for the complete interaction of the hydroxyl groups of cellulose. Epoxysmole was chosen as the matrix. Composites with different contents of graft copolymers of cellulose and polyester were obtained. The surface structure of the composites was analyzed using scanning electron microscopy. The uniformity of the filler distribution in the matrix and the uniformity of the structure were shown regardless of the amount of filler. The main physical, mechanical, and operational characteristics of the composites weredetermined. In comparison with the unfilled composite, the samples demonstrated an 8% increase in the strength of composites at a content of 0.5% and a 20% increase at a content of 1%; a significant increase was also observed in the modulus of elasticity (200% and 270%, respectively), and the deformation index increased with a low filler content, followed by a slight decrease. Thermal analysis of the composites did not show a noticeable decrease in the thermal stability of the samples.

Bisompatible and biodegradable graft copolymers of cellulose and polyester resin were obtained with the possibility of use in various polymer matrices for medical purposes.

Introduction: Textile finishes have long been used to add functional properties to fabrics. These functionalities can be applied to textile substrates in various ways. However, one of the most common approaches is through the use of microcapsules, which provide protection to the encapsulated active compounds against potential adversities. Microcapsules are widely employed in various fields, including textiles, pharmaceuticals, and cosmetics. In the textile sector, they are used in the development of biofunctional textiles, which serve as vehicles for transporting encapsulated actives, allowing them to come into contact with the skin and perform cosmetic or medicinal functions. This study introduces a novel textile finish based on microcapsules containing lemongrass essential oil and salicylic acid, produced via in situ polymerization—a unique combination not previously reported in the literature. Methods: The microcapsules were characterized using scanning electron microscopy (SEM) for morphology, dynamic light scattering (DLS) for particle size, and Fourier-transform infrared spectroscopy (FTIR) for chemical composition. Loading efficiency, thermal stability (via thermogravimetric analysis, TGA), and free formaldehyde detection were assessed to ensure safety compliance. The microcapsules were applied to 100% cotton fabric using the pad-dry technique, with functionalization confirmed by SEM and TGA. Results: SEM revealed an irregular morphology, while DLS indicated an average particle diameter of 1.95 µm. FTIR confirmed the chemical composition, and loading analysis showed 67.90 ± 1.41% lemongrass oil in the core. TGA and formaldehyde detection confirmed compliance with Brazilian Health Regulatory Agency (ANVISA) safety standards. Successful application to cotton fabric was validated by SEM and TGA, demonstrating effective functionalization. Conclusion: The microcapsules produced via in situ polymerization show significant potential for dermocosmetic applications and textile functionalization. This study underscores the innovative potential of combining lemongrass oil and salicylic acid in microcapsules, paving the way for new cosmetotextile products and further exploration in this field.

Bacterial resistance is a major healthcare challenge caused by the misuse of antibiotics, leading to ineffective treatments for infections. In orthopedics and dentistry, biofilm formation on implants exacerbates the issue. A promising solution is quorum quenching, which disrupts bacterial communication, with lactonase enzymes showing potential to prevent biofilm and combat resistance.

In this work, Ti6Al4V alloy disks were polished, cleaned, and chemically treated with acid etching and oxidation to prepare the surface (Ti6Al4V CT). After UV activation (Ti6Al4V CT+UV) and calcium treatment (Ti6Al4V CT+UV+Ca), surfaces were functionalized with ST1 lactonase enzyme solution using a concentration of 1000 µg/mL, creating a Ti6Al4V CT+UV+Ca+ST1 1000 sample.

The modified titanium alloy is biocompatible¹ and serves as an excellent platform for biological functionalization. Once confirmed that the enzyme functionalization was carried out through a zeta potential analysis, real-time quantitative PCR revealed that neither the enzyme nor the functionalized titanium samples exhibit traditional antibacterial properties. However, they effectively reduce gene expression related to quorum sensing and virulence factor production in Pseudomonas aeruginosa. Similar effects were not observed with E. coli and S. aureus.

This study demonstrates the potential of ST1 lactonase-functionalized Ti6Al4V alloys to combat bacterial resistance. These findings highlight the promise of quorum quenching as a strategy for biofilm prevention, particularly in implant applications.

¹Surface modification of Ti–6Al–4V alloy for biomineralization and specific biological response: Part I, inorganic modification. (Ferraris et al., 2011)

Background: Needle penetration is crucial in various fields, especially in medical applications. Recent studies indicate that, in addition to size and point type, needle coatings significantly impact penetration forces. During needle insertion, the needle body directly contacts biological soft tissue, often leading to tissue adhesion and varying degrees of tissue damage. Therefore, coating needles can substantially reduce tissue trauma during insertion.

Methods: Optimizing the needle surface, particularly through coatings, can effectively address these issues. Various coatings, including biocompatible hydrophilic, metallic glass, silicone, and composite materials, have been studied. These coatings can reduce friction during insertion, minimize tissue adhesion, and decrease insertion and extraction forces.

Results: Coating surgical needles with a composite material (Polytetrafluoroethylene, Polydopamine, and Activated Carbon) reduced insertion and extraction forces, showing promising results with a reduction in insertion force by up to 49% and tissue damage by 39% in bovine kidney experiments. This coating also minimized tissue damage during percutaneous procedures. A biocompatible hydrophilic coating on a needle reduced tissue damage and adhesion during a puncture biopsy procedure. A silicone coating enhanced the durability and sharpness of surgical needles when passing through certain tissues, and a metallic glass coating on tattoo needles reduced skin trauma and improved tattoo quality.

Conclusions: These innovations in needle coatings show promise for minimizing tissue damage, improving precision, and promoting faster healing.

Abstract

The use of nanostructured and biodegradable coatings is of great importance in the field of biomedical engineering with regard to implantable medical devices, drug delivery systems and even controlled release mechanisms for medicine. These types of coatings utilize the advantages of nanotechnology to improve the surface properties of diverse materials, which include structures that are more compatible with biological tissues, enhanced mechanical strength, and functionalization. Coatings that include nanoparticles or nanofibers, for example, are referred to as nanostructured coatings. These coatings have enhanced antimicrobial properties, greater cell adhesion, and controlled release of drugs. Such characteristics make them suitable for the treatment of wounds, surgical implants, and tissue engineering scaffolds.

Some biodegradable coatings are fabricated from polylactic acid (PLA), polycaprolactone (PCL), and even chitosan, which reduce environmental impacts and do not require surgical extraction after application. They are especially useful in drug-eluting systems, where the degradation of the coating material after the process is used to ensure that controlled and sustained release of the drug is achieved, which dramatically increases the desirable therapeutic action and significantly decreases side effects.

It is also noteworthy that the merging of nanostructured features and biodegradable materials produces hybrid coatings suitable for stents, orthopedic implants, and biosensors, which employ composite materials with composite properties. These coatings also aid in early diagnosis and treatment through personalized medicine. As materials science and nanotechnology progress, the world’s focus is on integrating the use of nanostructured and biodegradable coatings, which will surely help modern biomedical applications with their great innovations, safety, and improvements in patient treatment.

Magnesium (Mg) and its alloys have recently arisen as promising biomaterials fulfilling the requirement of functional bone tissue support and aid to its regeneration. Permanent non-biodegradable implants such as titanium (Ti), cobalt–chrome, and stainless steel can cause inflammation, toxicity (infection), and sometimes improper bone healing. Thus, an additional or alternative surgical procedure is required to remove these implants from the body after the healing process. Mg shows bioresorbable, biodegradable, and biocompatible properties. Furthermore, it degrades without causing any toxicity, and henceforth, additional surgery can be avoided. Apart from its biocompatible properties, it also demonstrates good mechanical properties like low density and elastic modulus in the range compatible with bone structures [3].

Despite all the virtues of Mg, its swift corrosion rate and degradation in an in vivo atmosphere may cause early fracture before complete bone healing, greatly hindering its application as an implant material. Furthermore, gas evaluation due to fast degradation may cause encapsulating processes. To overcome such corrosion behavior, a refinement on Mg-based screw implants by a PEO (plasma electrolytic oxidation) process is
developed, ensuring a dimensional stability of 2 months in a corrosive environment. The current work was accomplished under various PEO regimes to obtain the desired thickness and other essential properties best suited for Mg-based screw implants.

The microstructure, chemical composition, and surface properties of the PEO were investigated and compared via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). SEM/EDS analysis illustrated the morphology of PEO, the elemental/phase distribution, and the formed barrier layer at the substrate/oxide layer interface for different process parameters, drastically altering the corrosion behavior and mechanical properties. The corrosion resistance of various PEO surfaces was studied by using electrochemical analysis techniques such as electrochemical impedance spectroscopy in 0.9-wt% NaCl solution at 36°C. The results showed significant improvement in the corrosion behavior of PEO samples when compared with uncoated Mg surfaces.

We developed a cell sheet engineering platform based on poly(4-vinylpyridine) (P4VP) polymer brushes modified with metal nanoparticles (CuNPs) and evaluated their physicochemical properties and biocompatibility. The fabricated coatings exhibited antibiocidal activity and biocompatible characteristics, as well as thermoresponsive behavior, enabling temperature-dependent modulation of their properties.

The chemical composition and surface morphology of the coatings were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Additionally, the release of CuNPs from the P4VP coatings was quantified through XPS.

The thermoresponsive nature of the coatings was verified by measuring water contact angles and collecting UV-Vis absorbance spectra as a function of temperature.

The antimicrobial properties of the CuNP-modified P4VP brushes were assessed through microbiological tests targeting contact- and release-based killing mechanisms, both of which demonstrated significant antibacterial efficacy.

To assess brushes’ biocompatibility, protein adsorption onto the polymer brushes was evaluated using immunofluorescence and immunochemistry assays. Furthermore, retinal pigment epithelium cells (ARPE-19 line) were cultured on the fabricated coatings, and cell viability was analyzed using the MTT assay. The results indicated sustained cell viability over time, suggesting biocompatibility of the coatings.

The thermoresponsive behavior of the P4VP brushes facilitated the spontaneous detachment of ARPE-19 cell sheets upon cooling. Post-detachment observations confirmed maintained viability of the released cells.

In conclusion, our study demonstrates the feasibility of creating biocompatible, thermoresponsive polymer coatings capable of spontaneous cell sheet detachment. These antibacterial, thermoresponsive coatings hold promise for applications in cell sheet engineering platforms for therapeutic purposes.

The study was funded by the “Research support module” as part of the “Excellence Initiative - Research University” program at the Jagiellonian University in Kraków (RSM/80/CA).

Additive manufacturing (AM), especially titanium (Ti) alloys, enables the production of complex-shaped components with minimal material and energy waste, whose design and surface functionalization are critical for biomedical applications. However, as-printed titanium alloys often exhibit inherent defects, such as cracks and unmelted particles, resulting from the heating regimes during printing. These surface irregularities can significantly influence biocompatibility. Their biological impact remains poorly understood, emphasizing the need to address these defects to enhance cell–material interactions on titanium surfaces. In this study, the cytocompatibility of AM Ti meshes was evaluated after applying three surface treatments: chemical etching, electropolishing, and a combination of both. Surface features were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to assess the removal of unmelted particles and changes in surface roughness. The results showed that chemical etching effectively removed unmelted particles, while electropolishing significantly reduced surface roughness. The combination of both treatments resulted in clean, uniformly smooth surfaces.

The cytocompatibility of the samples was assessed using the Prestoblue assay with the materials in contact with cells after 24 h, 96 h, and 168 h. After 15 days, cells were fixed and labelled for nuclei and actin staining to evaluate adhesion and spreading on the material surfaces. Cell adhesion to the surfaces was also analyzed by SEM/EDS. The findings revealed that all samples were cytocompatible. Nevertheless, the ones treated with the combined etching and electropolishing approach and electropolishing alone favoured the formation of a monolayer on the surfaces. These results confirm the effectiveness of the studied surface treatments in enhancing cell–surface interactions, underscoring their potential for biomedical applications.

Novel food packaging films based on biopolymers combined with antimicrobial inorganic nanostructures (NSs) have been developed to replace traditional plastics. However, little is known about their possible toxicity and oral bioaccessibility if accidentally ingested.

In this contribution, we studied the zinc bioaccessibility of ZnO NSs-modified alginate films, setting up a dedicated flow system utilizing sequential injection analysis (SIA) for its automatic evaluation over time through a dynamic approach mimicking human digestion by gastric fluid (GF).

Crosslinked ZnO NSs/alginate films were thus fabricated. NSs were prepared using an electrochemical–thermal method and added directly to the alginate solution. Films were formed by dry casting and crosslinked with Ca²⁺ solution. ICP-OES characterization was carried out to verify the real zinc content in the films before testing, as compared to the nominal mass content. An SIA system was designed to profile the temporal release of zinc ions from nanocomposites. The analysis started by pumping synthetic GF onto film pieces in a flow-through container under fluidized-bed conditions, and then, at fixed times, part of this fluid was automatically retrieved and mixed on-line with borate buffer and Zincon for in-line spectrophotometric detection. A sudden release occurred within the first 3 minutes of extraction followed by a more gradual release.

The proposed approach based on a dynamic extraction method using an automatic SIA system is deemed an interesting solution for the high-throughput assessment of metal ion bioaccessibility in antimicrobial-containing packages without using in vivo or in vitro cell tests. Moreover, it could be applied to other targets (e.g., plasticizers, antioxidant compounds) just by modifying the analytical method.

AVM acknowledges funding from the European Union—NEXTGENERATIONEU—NRRP MISSION 4, COMPONENT 1. MO and MM acknowledge financial support from the Spanish Ministry of Science and Innovation (MCIN), and the Spanish State Research Agency (AEI/10.13039/501100011033) through the project PID2020-117686RB-C33 (MCIN/AEI).

Introduction. Hydroxyapatite coatings are a rapidly expanding field that focuses on the addition of various elements to obtain tunable properties. The electrochemical techniques enable the assessment of coatings based on hydroxyapatite doped with various elements that promote cell growth and osteogenic differentiation while exhibiting antibacterial properties.

Methods. The aim of this study was to obtain hydroxyapatite-based coatings doped with Sr and Ag through the galvanostatic pulse technique. The electrolytes were obtained by subsequently dissolving in ultra-pure water of the following chemical reagents, Ca(NO₃)₂·4H₂O, NH₄H₂PO₄, Sr(NO₃)_2, and AgNO₃ in different concentration with respect to a Ca/P ratio of 1.67. The electrolyte’s pH was adjusted to 5. The coatings were characterized in terms of morphology, elemental and phasic composition, wettability, and roughness. Subsequently, the hydroxyapatite-based coatings were tested in vitro by evaluating their electrochemical behavior and their cellular response to preosteoblast cell cultures.

Results and Discussion. The galvanostatic pulse technique has allowed the development of uniform and compact hydroxyapatite-based coatings, undoped and doped with Sr and/or Ag, that registered a Ca/P ratio closer to 1.67. The XRD analysis highlighted hydroxyapatite as the main phase in all coatings. The contact angle analysis with simulated body fluid (SBF) showed that all coatings have a strong hydrophilic character, registering contact angles within 8° - 10°. The average roughness (Ra) registered values between 300 and 700 nm and a tendency toward a symmetrical topography. The best electrochemical behavior was registered by undoped HAp-based coatings. The studies regarding the response of the preosteoblasts indicated that these surfaces favor the adhesion and proliferation capacity of preosteoblasts, while the addition of Sr exerted beneficial effects on preosteoblast response, irrespective of the presence or absence of Ag.

Conclusions. Thus, the undoped and doped hydroxyapatite coatings with strontium and/or silver obtained at pH 5 denoted enhanced and tunable properties for medical applications.