IntroductionThe development of photosensitizers with high tissue penetration and strong antimicrobial activity against pathogenic microorganisms is at the forefront of antimicrobial photodynamic therapy research. Reducing the aggregation of photosensitizers (PS) in aqueous solutions through the addition of amphiphilic polymers can enhance their ability to generate reactive oxygen species (ROS) and, consequently, improve the efficacy of photodynamic treatment. Previously, we demonstrated that amphiphilic polymers increase the singlet oxygen generation activity of porphyrin photosensitizers and certain dyes by promoting the disaggregation of hydrophobic PS molecules.Results and DiscussionIn the present study, we performed a comparative investigation of photodynamic treatment of model wounds in mice using methylene blue dye and Fotoditazin as PS, both in the presence and absence of the amphiphilic polymer Pluronic F108. In addition, sodium alginate was incorporated into the photosensitizing systems to provide an additional antibacterial effect on the wound.ConclusionThese findings provide a theoretical basis for the application of photosensitizer–polymer systems containing sodium alginate in antimicrobial photodynamic therapy for difficult-to-treat wounds.

Hybrid fluorinated copolymers containing POSS moieties along with fluorinated homopolymers were synthesized via organocatalyzed atom transfer radical (co)polymerization (O-ATRP) of fluoroalkyl methacrylate (FMA) and a POSS-based monomer (IBSS) using perylene as a photocatalyst. Linear and four- and eight-armed star-shaped (co)polymers in a wide range of molecular weights with Mn(SEC) up to 53,100 g/mol for poly(FMA), 22,700 g/mol for poly(IBSS) and 87,300 g/mol for poly(FMA-co-IBSS) were successfully prepared. During polymerization, C-F activation was found to induce chain transfer and branching reactions, contributing to structural diversity. A mechanism for chain transfer to the polymer resulting in branching was proposed, applying density functional theory (DFT). Films based on the obtained (co)polymers showed tunable morphology, high thermal stability (up to 306 °C) and hydrophobicity, with water contact angles reaching 98°.

Background: Fascicular turnover flap (FTF) is a donor-sparing option for segmental facial nerve repair. This study compared autologous nerve grafting with proximally based and distally based FTF in a rat facial nerve model. Methods: Adult male Wistar rats were randomized to autograft, proximal FTF, or distal FTF (n = 8 per group). A single additional animal with an untreated defect served as a qualitative histological reference. The prespecified primary endpoint was whisker motion amplitude at week 8; the secondary endpoints were central section histomorphometry (nerve tissue area, µm2) and variability metrics (IQR, SD, and coefficient of variation) as measures of reproducibility. Non-parametric tests (Kruskal-Wallis; Mann-Whitney U) were used; pairwise functional comparisons were Holm-corrected; and effect sizes were expressed as Cliff's δ. Results: At week 8, the overall functional comparison was significant (Kruskal-Wallis p = 0.047), but no pairwise contrast remained significant after Holm correction. Functional recovery was highest in the autograft group, followed by proximal FTF and distal FTF. Both FTF groups showed lower inter-animal variability than autograft for the week-8 functional endpoint, with the distal FTF showing the lowest dispersion. Central section nerve area comparisons did not reach global significance; effect sizes and descriptive statistics favored autograft, and a single unadjusted pairwise contrast (autograft > proximal FTF) should be interpreted cautiously. Conclusions: Both FTF configurations achieved measurable functional and structural regeneration while avoiding an additional free donor nerve graft. Within an 8-week window, autograft remained the benchmark. Between FTF variants, distal FTF produced more stable functional outcomes, but this did not translate into superior functional recovery. Confirmation in larger, balanced cohorts with longer follow-up and vascular/neural labeling is warranted.

ABSTRACT Liver fibrosis is the common consequence of liver injury caused by a variety of chronic liver disorders. This condition leads to the development of more severe complications, particularly cirrhosis and hepatocellular carcinoma. Despite abundant studies, the fundamental cell and molecular mechanisms of liver fibrosis are still unknown. There are many key players involved in the initiation and progression of liver fibrosis. Thus, the specific type of underlying disease and the study's objectives should be considered while choosing suitable models for liver fibrosis. Numerous in vitro and in vivo models have been generated to investigate liver fibrosis and proposed for drug screening and toxicology; however, there are no ideal in vitro models for drug discovery yet. In this review, we introduced the available in vitro models and highlighted certain platforms such as organoids and liver‐on‐a‐chip for investigating liver fibrosis. Furthermore, we discussed the current challenges and potential application of each model.

Traumatic injuries to the craniofacial skeleton, along with diseases and structural defects affecting oral tissues—including teeth, gums, and the periodontal complex—are among the most prevalent pathological conditions in humans. Over the course of a lifetime, nearly everyone requires some form of dental or maxillofacial care. While current routine clinical procedures—such as surgical reconstructions, tissue grafting, and prosthetic restoration—provide varying degrees of therapeutic benefit, they often fail to fully restore the complex architecture and functions of craniofacial tissues. This limitation primarily reflects the intricate organization of the maxillofacial region, in which soft and hard tissues are tightly coordinated within a precisely regulated anatomical framework. Emerging cell-based biofabrication technologies, such as organoids, three-dimensional bioprinting, and microfluidic organ-on-chip systems, offer promising strategies for improving tissue equivalents and in vitro tissue models, bringing their architecture and functional properties closer to native tissues. In this review, we examine recent advances in craniofacial cell-based biofabrication, focusing on the development of oral tissue organoids, advanced bioprinting techniques—including in situ bioprinting, four-dimensional bioprinting, and volumetric bioprinting—and the implementation of craniofacial organ-on-chip systems. Furthermore, we discuss the principal challenges currently limiting the field and outline prospective directions that may guide the next generation of cranial and oral tissue engineering.

Owing to their high strength characteristics, chemical stability, and piezoelectric activity, vinylidene fluoride (VDF) copolymers have become promising materials for creating implants to replace bone tissue defects. However, a significant drawback of these materials is the biological inertness of their surface, which leads to unsatisfactory integration with the patient’s bone tissue. In this study, we propose a single-step approach for immobilizing hydroxyapatite (HAp) on the surface of porous implants made of vinylidene fluoride and tetrafluoroethylene copolymer (P(VDF-TeFE)). This method consists of treating the surface of the product with a mixture of solvents while simultaneously capturing HAp microparticles. Using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), it was shown that the proposed method preserves the morphology of model implants (pore diameter and printed line thickness) and allows HAp to cover up to 63 ± 14% of their surface, reaching concentrations of calcium and phosphorus up to 6.0 ± 1.3 and 3.6 ± 0.7 at. %, respectively, imparting superhydrophilic properties to them. Optical profilometry revealed that the surface roughness of samples increased by more than seven times as a result of HAp immobilization. X-ray diffraction analysis (XRD) confirmed that the piezoelectric phase of P(VDF-TeFE) is preserved after treatment, as are the compressive strength characteristics of the samples. Hydroxyapatite immobilization significantly improved the adhesion and osteogenic differentiation of multipotent stem cells cultured with P(VDF-TeFE)-based samples. Thus, the proposed method can significantly enhance the biological activity of implants based on the piezoelectric VDF copolymer.

Calcium alginate (CaA) xerogels and aerogels were evaluated as carriers for Rose Bengal (RB) in singlet-oxygen-generating systems intended for photodynamic applications. Hybrid CaA/polyvinylpyrrolidone (PVP) matrices were also prepared. Nitrogen sorption showed that the CaA xerogels(A) were mesoporous, with a specific surface area of SBET ~225 m2/g and a mean pore diameter of approximately 9.3 nm; the corresponding SBET values were approximately 300 m2/g for the aerogels and below 1 m2/g for the xerogels. RB introduced during xerogel formation from water was retained in the matrix and was not released into phosphate-buffered saline (PBS, pH 7.2). By contrast, RB loaded from isopropanol was released from the xerogels(A) and aerogels, with the fastest release observed for CaA aerogels. RB incorporated into xerogels(A) and aerogels retained singlet-oxygen-generating activity. In air, the highest luminescence response was observed for RB immobilized in hybrid CaA/PVP aerogel films containing approximately 10 wt% PVP. These findings suggest that such systems hold promise for applications in photodynamic therapy of superficial skin injuries. Xerogels(A) are also attractive carrier candidates because they avoid supercritical drying and, for the CaA xerogel(A) studied here, released 50% of the loaded RB within approximately 5 min.

Three-dimensional (3D) cell spheroids are widely used asin vitrotissue models, yet quantitative understanding of their morphogenesis remains limited. We present an integrated experimental-computational framework to analyze, model, and modulate the compaction of cell aggregates in agarose microwells of defined geometries. Custom 3D-printed stamps produced circular, square, and triangular microwells of equal cross-sectional area. Time-lapse imaging combined with AI-based segmentation enabled tracking of spheroid morphology, with circularity and projected area serving as quantitative descriptors of compaction. The process followed predictable exponential kinetics, with mesenchymal (HDF) spheroids compacting faster than epithelial (ARPE-19) ones. Computational fluid dynamics (CFD) simulations modeled spheroid rounding as a visco-capillary-driven process, where the extracted visco-capillary velocity unified experimental and simulated dynamics. Mechanical measurements by atomic force microscopy and compression confirmed that differences in surface tension predominantly governed the observed kinetics. Pharmacological modulation of cytoskeletal tension revealed that inhibition of contractility markedly altered spheroid formation dynamics, enabling the generation of stable, non-spherical aggregates. Using this principle as a shape-engineering strategy, we produced aggregates with distinct geometries (brick-like, prismatic, and star-shaped), characterized by an increased surface-to-volume ratio compared to conventional spheroids. Limitations of the approach include the use of pharmacological cytoskeletal modulation and constraints in geometric fidelity arising from printing resolution, agarose casting, cell filling, and intrinsic smoothing of sharp features during cell aggregation. Collectively, this work establishes a geometry-controlled platform for quantitative analysis of spheroid formation and mechanical behavior, and provides a versatile framework for designing cell aggregates with defined shapes.

Ewing sarcoma (ES) is a highly aggressive pediatric malignancy with limited treatment options and frequent development of drug resistance. In this case, novel drug delivery systems may overcome tumor resistance and improve therapeutic efficacy. We developed lactoferrin-chondroitin sulfate microparticles (Lf-ChS MPs) that can be loaded with the carbonic anhydrase II inhibitor OX72. Their physicochemical properties were characterized by AFM, FTIR, zeta potential, DSC/TGA, and drug release assays. In vitro cytotoxicity was evaluated in ES cell lines (A673, ES36, T69, and doxorubicin-resistant A673 cells), with 977hTERT fibroblasts as controls. Drug encapsulation significantly enhanced the antiproliferative activity of OX72 in ES36 and A673 cells, as well as in doxorubicin-resistant cells. Mechanistically, Lf-ChS-OX72 reduced FTH1 expression, indicating ferroptosis induction, with no influence on apoptosis. Lf-ChS microparticles provide a promising platform for OX72 delivery inducing ferroptosis-mediated cytotoxicity in doxorubicin-resistant sarcoma cells.

Calcium phosphate-reinforced polycaprolactone composites have gained a grown attention for the fabrication of bioresorbable scaffolds for bone tissue engineering. One limitation arose from the low lateral resolution of the conventional fused filament fabrication, which was overcome in this study by the implementation of advanced three-stage method of the polycaprolactone-amorphous calcium phosphate scaffold formation. Another challenge emerged from poor cell adhesion to the composite surface and low osteoinductivity, that was addressed by the surface modification approaches and the implementation of more soluble dispersed phase (amorphous calcium phosphate). Stabilized amorphous calcium phosphate nanoparticles were synthesized with three different carboxylate stabilizers. The addition of amorphous calcium phosphate led to the improved bending and tensile strength, disclosing the considerable interfacial binding energy between particles and polymer matrix. Furthermore, the modification of developed composites in acidic environment improved the stiffness, while alkaline treatment was shown to decrease stiffness and enhance roughness, providing additional cell adhesion sites. Applied three-stage composite scaffold fabrication method was shown to provide smooth rounded pores. The cytocompatibility assay showed the absence of negative effects from the modified amorphous calcium phosphate dispersed phase on the metabolic activity of mesenchymal stromal cells and revealed considerable cell adhesion on the composite surface with no negative effects on the mesenchymal stromal cells viability and morphology. Thus, developed fabrication method in combination with the proposed polycaprolactone-amorphous calcium phosphate composition showed enhanced mechanical and surface properties, as well as biocompatibility, providing a mineral-supportive microenvironment relevant to bone regeneration.

One of the common issues in the R&D of new drugs is the failure of clinical trials caused by the species-specific inadequacy of animal models to assess drugs’ efficiency and safety. Therefore, systems like organ-on-a-chip and, particularly, liver-on-a-chip (LOC) can be an efficient tool for recapitulating in vivo-like human physiology at the microscale. This review focuses on discussing LOC design, emphasizing its architecture and validation to reveal the trends in searching for a balance between biomimetics and functionality. We found that the huge variety of already published models can be divided into five groups based on their configuration complexity: flat one-channel, flat two-channel, vertically stacked multilayered, hexagonal-patterned, and multi-well chips. While researchers attempt to recapitulate the liver’s histology and its functions in detail by increasing the complexity of devices’ architectonics, industrial companies prefer to promote more simple and flexible solutions. Thus, the LOC designs of the future require neglecting some liver characteristics to make them standardizable and sustainable, which could facilitate their introduction into the market and clinics.

Neoadjuvant therapy (NAT) is a standard component of breast cancer treatment, yet response rates vary substantially across patients. Accurate prediction of pathological complete response remains an unmet clinical need to improve patient selection for NAT. This review summarizes current approaches of using computer vision to predict breast cancer response to NAT from histopathological slides. We examined studies employing computer vision and machine learning models on hematoxylin and eosin and immunohistochemically stained whole-slide images, focusing on morphological features of tumor cells, stroma and tumor-infiltrating lymphocytes associated with pathological complete response. Key morphological predictors of therapy resistance included low tumor cell density with cord-like patterns, necrosis, predominance of collagenous and fibroblast-rich stroma and tumor vascularization, while therapy sensitivity was associated with high nuclear staining intensity, high tumor cell density and lymphocyte infiltration. We highlighted the advantages of incorporating multimodal data to enhance predictive performance. Our analysis demonstrates that computer vision models can detect subtle morphological patterns that may be difficult for pathologists to evaluate, providing valuable insights for personalized therapy planning in breast cancer. Further development of cross-modal, interpretable artificial intelligence solutions may improve prediction accuracy and deepen our understanding of tumor biology relevant to NAT response.

Abstract Cell-based therapy has become an attractive option to restore the vocal folds (VF) after scarring. Despite that first clinical trials using mesenchymal stromal cells (MSC) suspension has been launched, there is still an issue of retaining cells at implantation site to prolong their effects. Therefore, cell spheroids are considered to be a part of next generation bioequivalents. This study aims to reveal the safety and efficacy of MSC spheroid-based bioequivalent in treating VF scars in comparison with cell suspension. To evaluate this approach in vivo, a rabbit vocal fold scar model was established in 48 male rabbits, which were allocated to four groups: untreated control, PEG-fibrin, PEG-fibrin with MSC suspension, and PEG-fibrin with MSC spheroids. In 3 months post operation, in group where the MSC suspension-based bioequivalent was implanted, the mature connective tissue was located beneath the epithelium without dystrophic changes and had a relatively loose ECM; the thickness of the lamia propria was higher than that in the intact VF. In group where we used the MSC spheroid-based bioequivalent the loose connective tissue consisted of longitudinally oriented collagen fibers, spindle-shaped fibroblasts; the lamia propria was relatively thin (116.42 ± 42.77 μm) and loose and did not differ from the intact VF. Both types enabled the VF restoration; nevertheless, the use of MSC spheroids lead to more efficient regeneration: the tissue architectonics and mechanical properties of the treated VF was more similar to those of the intact VF.

Portable handheld bioprinters represent a transformative advancement in personalized skin regeneration, bypassing the logistical constraints of stationary lab-based systems by enabling real-time, in situ fabrication of bioengineered constructs directly within the wound bed. This review aims to evaluate the current state of their development and clinical translation. One of the foci is placed on the stringent physicochemical requirements for bioinks, where we examined the critical balance between bioadhesion—facilitated by functional groups—and mechanical cohesion necessary for maintaining structural integrity during deposition, while RGD motifs are considered primarily as promoters of integrin-mediated cell adhesion. Preclinical studies have demonstrated promising effects of bioprinted constructs on wound healing and tissue organization; however, human evidence for handheld and direct in situ skin bioprinting remains limited, and clinical efficacy has yet to be established in controlled studies. Nevertheless, widespread adoption is hindered by inferior printing fidelity relative to stationary counterparts, a lack of standardized GMP-compliant bioink production, and regulatory ambiguity that impedes clear classification as either medical devices or biologics. Practical barriers, including intraoperative sterility assurance and operator training, also remain unresolved. Looking ahead, we discuss how the convergence of, in particular, artificial intelligence for real-time wound morphometry, closed-loop process control, and smart, self-healing biomaterials promises to surmount these obstacles. We conclude that these synergistic innovations may propel handheld bioprinters from experimental prototypes toward clinical tools with the potential to reshape reconstructive surgery and emergency wound care, although their clinical value will require validation in appropriately designed human studies.

Background/Objectives: Alveolitis, or “dry socket,” is a common complication after tooth extraction, associated with pain, inflammation and delayed healing. Standard surgical treatments are often invasive and insufficient. Laser therapy offers antimicrobial, anti-inflammatory and regenerative effects. This study aimed to compare the efficacy of 980 nm monolaser therapy and 980 nm and 1550 nm dual-wavelength therapy on alveolar socket healing in a rabbit model. Methods: In vitro tests evaluated bactericidal effects of 980 nm laser exposure. Eighteen adult male chinchilla rabbits underwent the extraction of the first incisors with the prevention of clot formation to model alveolar socket healing. On day 3, animals were randomized to three groups: mechanical curettage and antiseptic irrigation, 980 nm diode laser therapy, or combined 980 nm + 1550 nm therapy. Clinical parameters (hyperemia, edema, pain, socket closure) were assessed up to day 7. Histological and microbiological analyses were performed on days 7 and 12. Results: Laser therapy showed superior outcomes compared to mechanical treatment. In vitro, 980 nm exposure eradicated microorganisms after 3 s. By day 7, hyperemia decreased to 0.7 ± 0.6 points in the dual-laser group, versus 2.0 ± 0.0 (980 nm) and 3.0 ± 0.0 (mechanical). Complete socket closure occurred in 33% with mechanical treatment and in 67% of sites in the dual-laser group. Pain was fully resolved only after dual-laser therapy. Histology confirmed more organized granulation tissue and angiogenesis in the dual-laser group. Conclusions: Dual-wavelength laser therapy demonstrated superior anti-inflammatory, antimicrobial and regenerative effects compared with diode monotherapy and mechanical treatment. These findings highlight its promise as a minimally invasive approach for managing alveolitis, warranting further clinical evaluation.

Osteomyelitis, a severe bone infection, poses significant challenges due to antibiotic resistance and limited efficacy of conventional treatments, which often rely on non-degradable carriers with burst antibiotic release.

Periodontal regeneration remains one of the most demanding challenges in oral bioengineering due to the structural complexity of the periodontium and the inflammatory microenvironment accompanying disease. Conventional surgical and pharmacological therapies often fail to achieve full restoration of bone, ligament and cementum, prompting the development of cell-based and biomaterial-assisted approaches. This review summarizes current advances in cellular technologies for periodontal regeneration, emphasizing the biological rationale, material design and delivery methods shaping next-generation treatments. We discuss stem-cell-based strategies employing periodontal ligament, dental pulp and mesenchymal stem cells, their paracrine and immunomodulatory roles, and how their therapeutic potential is enhanced through integration into engineered scaffolds. Recent progress in hydrogel systems, microspheres, decellularized matrices and 3D bioprinting is analyzed, highlighting how structural cues, bioactive nanoparticles and gene-modified cells enable multi-tissue regeneration. Emerging delivery and biofabrication techniques, from manual seeding to automated and in situ printing, are reviewed as key determinants of clinical translation. The convergence of bioprinting precision, immune-responsive biomaterials and personalized cellular constructs positions periodontal bioengineering as a rapidly maturing field with strong prospects for functional restoration of diseased oral tissues.

Chronic wounds (CWs) represent a growing global health concern with profound clinical and socioeconomic implications. Studies indicate that approximately 15% of CWs remain unhealed one year after the initial treatment. At the same time, it is assumed that from 1% to 2% of the population of developed countries will suffer from chronic wounds during their lifetime. CWs severely impair patients’ quality of life. Current therapies (compression bandages, antibiotics, hyperbaric oxygen, and skin grafts) face limitations, including toxicity, contraindications, inefficacy in patients with comorbidities like diabetes, and high cost. Biological nanoparticles (BNPs), particularly extracellular vesicles (EVs), emerge as transformative solutions due to their innate biocompatibility, targeted biodistribution, and multifunctional regenerative properties. This review examines the mechanisms by which BNPs promote CW healing and drug delivery. Innovative BNP delivery platforms (chitosan hydrogels, alginate films) are evaluated, enabling sustained release and responsiveness to the wound microenvironment. Clinical advances, including exosome-laden hydrogels that accelerate healing in diabetic ulcers, underscore BNPs’ potential to overcome conventional therapy limitations. By addressing the challenges of both pathophysiological complexity and healthcare system burden, BNPs demonstrate the potential to improve patient outcomes in the management of chronic wounds.

Background/Objectives: Osteonecrosis of the femoral head (ONFH) is a common condition in hip surgery, which is characterized by the death of bone cells due to disruption of the blood supply and ultimately irreversible destruction of the hip joint. As a result of the COVID-19 pandemic, a significant increase in the incidence of ONFH has been identified. To better understand the pathogenesis of ONFH in the context of COVID-19, our research aimed to determine pathomorphological changes in articular tissues specific to post-COVID-19 ONFH. Methods: Using morphological, morphometric, and statistical methods, the femoral heads after hip arthroplasty were retrospectively studied in patients with post-COVID-19 ONFH (n = 41) compared to a non-COVID-19 group of patients (n = 47). Results: Our results revealed that the key morphofunctional biomarkers of post-COVID-19 ONFH were clusters of mast cells, extensive areas of fibrosis, numerous arterial and venous thrombi, and giant cell granulomas. The potential relationship of those morphological features with the action of the SARS-CoV-2 coronavirus was discussed. Conclusions: Mast cells have been proposed as the leading players that may trigger the main molecular and cellular mechanisms in the development of post-COVID-19 ONFH and can be considered a diagnostic sign of the disease.

Filamin C (FLNC) is a structural protein of muscle fibers. Mutations in the FLNC gene are known to cause myopathies and cardiomyopathies in humans. Here we report the generation by a CRISPR/Cas9 editing system injected into zygote pronuclei of two mouse strains carrying filamin C mutations—one of them (AGA) has a deletion of three nucleotides at position c.7418_7420, causing E>>D substitution and N deletion at positions 2472 and 2473, respectively. The other strain carries a deletion of GA nucleotides at position c.7419_7420, leading to a frameshift and a premature stop codon. Homozygous animals (FlncAGA/AGA and FlncGA/GA) were embryonically lethal. We determined that FlncGA/GA embryos died prior to the E12.5 stage and illustrated delayed development after the E9.5 stage. We performed histological analysis of heart tissue and skeletal muscles of heterozygous strains carrying mutations in different combinations (FlncGA/wt, FlncAGA/wt, and FlncGA/AGA). By performing physiological tests (grip strength and endurance tests), we have shown that heterozygous animals of both strains (FlncGA/wt, FlncAGA/wt) are functionally indistinguishable from wild-type animals. Interestingly, compound heterozygous mice (FlncGA/AGA) are viable, develop normally, reach puberty and it was verified by ECG and Eco-CG that their cardiac muscle is functionally normal. Intriguingly, FlncGA/AGA mice demonstrated better results in the grip strength physiological test in comparison to WT animals. We also propose a structural model that explains the complementary interaction of two mutant variants of filamin C.