A biodegradable multifunctional nanofibrous membrane for periodontal tissue regeneration

Advances of functional nanomaterials as either therapeutic agents or delivery systems in the treatment of periodontitis

Periodontitis is a common chronic inflammatory disease primarily caused by pathogenic microorganisms in the oral cavity. Without appropriate treatments, it may lead to the gradual destruction of the supporting tissues of the teeth. While current treatments can alleviate symptoms, they still have limitations, particularly in eliminating pathogenic bacteria, promoting periodontal tissue regeneration, and avoiding antibiotic resistance. In recent years, functional nanomaterials have shown great potential in the treatment of periodontitis due to their unique physicochemical and biological properties. This review summarizes various functionalization strategies of nanomaterials and explores their potential applications in periodontitis treatment, including metal-based nanoparticles, carbon nanomaterials, polymeric nanoparticles, and exosomes. The mechanisms and advances in antibacterial effects, immune regulation, reactive oxygen species (ROS) scavenging, and bone tissue regeneration are discussed in detail. In addition, the challenges and future directions of applying nanomaterials in periodontitis therapy are also discussed.

Development of MgO-loaded PLA/dECM antibacterial nanofibrous membranes for enhanced gingival regeneration

Clinically, gingival tissue repair is challenging due to the complex oral microbial environment and inflammation. The development of gingival membranes using tissue engineering techniques offers a promising solution to this issue. This study focuses on developing a nanofibrous gingival membrane, combining polylactic acid (PLA), decellularized extracellular matrix (dECM), and magnesium oxide (MgO) nanoparticles. Electrospinning was used to fabricate membranes with varying ratios of PLA, dECM, and MgO, and their mechanical, antibacterial, and cell-proliferation properties were evaluated. NIH-3T3 and rat gingival fibroblast (RGF) cells were cultured on the membranes to assess biocompatibility. A rat model with gingival defects was used to test in vivo tissue regeneration. It was indicated that the antibacterial nanofibrous membranes with MgO showed enhanced antibacterial effects and reduced inflammation, and promoted gingival tissue repair.

Advances in harnessing biological macromolecules for periodontal tissue regeneration: A review

Periodontitis is a chronic multifactorial inflammatory oral disease that can lead to gingival recession, destruction of the periodontal ligament, alveolar bone loss, and tooth loss. Solutions for periodontal tissue regeneration utilize biological macromolecules, including natural ones (such as collagen (COL), alginate (ALG), chitosan (CS), silk fibroin (SF), hyaluronic acid (HA), etc.), inorganic ones (such as hydroxyapatite (HAp), β-tricalcium phosphate (β-TCP), bioactive glass (BG), etc.), synthetic, composite, and nanomaterials. Carrier materials, including hydrogels, nanofibers, nanoparticles, microneedles, and thin films, are used to effectively deliver therapeutic agents and biological factors such as stem cells, bioactive molecules, and genes, so as to promote the elimination of bacteria and tissue regeneration at the damaged periodontal sites. This review mainly focuses on the latest progress of biological macromolecules and tissue engineering technologies in periodontal regeneration in recent years. It aims to inspire the design and development of innovative biomaterials and delivery systems for novel regenerative periodontal treatments.

Osteogenic surgical sutures for tendon traction and fixation: A model of achilles tendon sleeve avulsion

Currently, the repair of Achilles tendon sleeve avulsion is a challenge due to their limited research and particularly difficult treatment. In tendon repair surgery, the construction of bone tunnels is required for the suspensory fixation of ruptured tendon by sutures. However, due to the biologically inert of commonly used tendon sutures, postoperative fixation instability, bone tunnel enlargement, and even tendon reconstruction failure can easily occur under stressful conditions. In this study, core-spun nanoyarns containing β-tricalcium phosphate (β-TCP) were prepared by electrospinning to serve as surgical sutures for tendon traction and fixation. The suture of 6 core-spun nanoyarns spun again into one strand had stronger mechanical properties, which could effectively pull the tendon. The silk fibroin micron yarn of the suture core layer and the polycaprolactone/silk fibroin/β-TCP nanofibers of the shell layer demonstrated favorable biocompatibility, which facilitated cell adhesion and expression in the tendon and bone. In the repair surgery of the Achilles tendon sleeve avulsion in rabbits, compared with non-degradable and high mechanical properties commercial sutures, the β-TCP in the nanofibers of sutures could induce osteogenesis, thereby reducing the gap in the bone tunnel and preventing enlargement of the bone tunnel. In conclusion, the suture could weave the ruptured tendon, fix the tendon to the bone, promote the formation of new bone in the bone tunnel, avoid the instability of the existing commercial sutures to the bone tunnel, and ultimately improve the success rate of tendon repair surgery. STATEMENT OF SIGNIFICANCE: Nowadays, there is very limited research on the Achilles tendon sleeve avulsion model. This model presents challenges due to inadequate tendon tissue in the calcaneus for direct repair and insufficient bone tissue on the avulsed tendon for fixation. The incidence of this model is low, but treatment once it occurs is particularly difficult. In this study, we proposed to compound osteogenesis-promoting β-TCP materials onto nanoyarns to prepare surgical sutures that could weave the ruptured tendon, fix the tendon to the bone, induce osteogenesis, and reduce the gap in the bone tunnel, thus avoiding the instability of the existing commercial sutures in the bone tunnel, and ultimately improving the success rate of the surgery.

Biodegradable Piezoelectric Janus Membrane with Enhanced Antibacterial and Osteoinductive Properties for Periodontitis Therapy

An ideal guided bone regeneration (GBR) membrane for periodontitis treatment should incorporate biocompatibility, biodegradability, mechanical strength, antibacterial properties, and osteoconductivity. However, no commercially available GBR membrane meets all these criteria simultaneously. In this study, a novel biodegradable piezoelectric double-layered membrane is developed, with a non-piezoelectric Poly-L-lactic acid (PLLA) side facing the gingiva and a piezoelectric PLLA-ZnO side facing the alveolar bone. This asymmetric GBR membrane, with distinct fiber orientations and charge distribution, combines and synergizes mechanical strength, degradability, barrier function, antibacterial activity and osteogenic potential to enhance bone regeneration efficacy. The GBR membrane can effectively prevent fibroblast migration, inhibits bacterial infection, and promotes bone regeneration both in vitro and in vivo. In vitro testing shows good antibacterial rate against Porphyromonas gingivalis (P. gingivalis) and Staphylococcus aureus (S. aureus) after 10 min of ultrasound stimulation. Expression levels of osteogenic genes Bone morphogenetic Protein 2 (BMP2), Runt-related transcription factor 2 (RUNX2), Osteopontin (OPN) and Osteocalcin (OCN) are over twice that of the control. In a mouse P. gingivalis-mediated periodontitis model, our composite membrane demonstrates effective antimicrobial effects and promote bone regeneration after 2- and 4-weeks implantation, facilitated by mechanisms such as physical isolation, zinc ion release, piezoelectric effects, enhanced expression of osteogenic genes through activation of osteogenesis-related signaling pathways, underscoring its strong potential for GBR applications.

Biodegradable Piezoelectric Janus Membrane Enabling Dual Antibacterial and Osteogenic Functions for Periodontitis Therapy

Guided tissue regeneration (GTR) using barrier membranes is a common clinical approach for treating periodontitis-induced alveolar bone loss. However, conventional GTR membranes lack antibacterial and osteoinductive properties, limiting their effectiveness. Piezoelectric materials, which generate electrical outputs under chewing forces, offer antibacterial and bone-regenerative potential due to their oppositely charged surfaces. Inspired by this, a piezoelectric Janus membrane was developed for dual-function GTR therapy. Biodegradable poly(l-lactide) (PLLA) and PLLA/gelatin membranes were electrospun, annealed, and polarized to create the A-P(+)/PG(-) piezoelectric Janus membrane. Notably, in this Janus membrane, the outer surface of the PLLA side (A-P(+)) carries positive charges and is positioned toward the gingival tissue to kill bacteria via charge interactions; the inner surface of the PG side (PG(-)) holds negative charges and faces the alveolar bone defect, promoting bone growth through immunomodulation and enhanced mineralization. In a mouse model of periodontitis, the Janus membrane A-P(+)/PG(-) demonstrated dual functionality, effectively reducing inflammation, inhibiting bone resorption. The bone mineral density of A-P(+)/PG(-) reached 1637 ± 37 mg/cm3 at 8 weeks after surgery, which was superior to commercial collagen membranes lacking antibacterial properties. Overall, this study introduces an innovative approach, leveraging biodegradable piezoelectric PLLA to construct a versatile Janus GTR membrane with enhanced antibacterial and osteogenic activity for periodontitis treatment.

Customized Hydrogel System for the Spatiotemporal Sequential Treatment of Periodontitis Propelled by ZEB1

Advanced periodontitis initiates with Porphyromonas gingivalis (P. gingivalis) infection, which subsequently triggers chronic inflammation, immune imbalance, and ultimately causes alveolar bone resorption. Traditional periodontal treatment focuses on the elimination of triggering factors, but tend to ignore the improvement of the inflammatory microenvironment and the remodeling of the osteogenic mineralization space. Herein, zinc-aluminum layered double hydroxide nanosheets (LDHs) loaded with icariin (ICA) are encapsulated into a gallic acid (GA)-modified hydroxybutyl chitosan hydrogel (GA-HBC), giving rise to a customized hydrogel system named GA-HBC-LIC, which can sequentially actualize antibacterial, anti-inflammatory, and remineralization functions. A neutral chemical-humoral space is created for osteogenesis via means of sequential regulation by the smart hydrogel. Concomitantly, appropriate mechanical properties and degradation performance of the hydrogel provide a desirable physical space for remineralization. In the spatiotemporal modulation of the hydrogel, zinc finger E-box-binding homeobox 1 (ZEB1) target of released zinc ions (Zn2+) action promotes macrophage polarization from M1 to M2 phenotype, thereby remodeling the immune microenvironment and releasing cytokines conducive to tissue regeneration. In sum, this study highlights the critical role of sequential inflammation regulation and the maintenance of osteogenic space in the regeneration of periodontal tissues, offering new insights for the clinical management of periodontitis.

Design and application of antimicrobial nanomaterials in the treatment of periodontitis

Periodontitis is a chronic inflammatory disease induced by the microbiome, leading to the destruction of periodontal structures and potentially resulting in tooth loss. Using local drug delivery systems as an adjunctive therapy to scaling and root planning in periodontitis is a promising strategy. However, this administration method's effectiveness is constrained by the complexity of the periodontal environment. Nanomaterials have demonstrated significant potential in the antibacterial treatment of periodontitis, attributed to their controllable size, shape, and surface charge, high design flexibility, high reactivity, and high specific surface area. In this review, we summarize the complex periodontal microenvironment and the difficulties of local drug delivery in periodontitis, explicitly reviewing the application and design strategies of nanomaterials with unique properties in the distinct microenvironment of periodontitis. Furthermore, the review discusses the limitations of current research, proposes feasible solutions, and explores prospects for using nanomaterials in this context.

Linking Metastatic Behavior and Metabolic Heterogeneity of Circulating Tumor Cells at Single-Cell Level Using an Integrative Microfluidic System

Circulating tumor cells (CTCs) are pivotal biomarkers in tumor metastasis, however, the underlying molecular mechanism of CTCs behavioral heterogeneity during metastasis remains unexplored. Here, an integrative workflow is developed to link behavior characteristics to metabolic profiling within individual CTCs, which simulates the metastatic process on a microfluidic system and combined with single-cell mass spectrometry (MS) detection. Spheroid-derived HCT116 cells are tracked and extracted via a temporary vascular system, revealing various arrest patterns under biomimetic vascular shear flow. Downstream MS analysis characterizes 17 cellular metabolites and associates metabolic profiles with de-adhesion behaviors of the same CTCs, identifying a potential high-metastatic subpopulation with enhanced arrest ability and evaluating critical metabolites involved in metastasis pathways. Additionally, the metastasis-inhibiting effect of anti-tumor drug 5-fluorouracil by reducing high-metastatic cells in spheroids is elucidated. This approach offers a valuable opportunity to dissect the interplay of the metastatic behavior and metabolic profiles of CTCs and foster insights into the molecular mechanisms underlying behavioral phenotypes in the tumor metastasis process.

Tissue Mimetic Membranes for Healing Augmentation of Tendon-Bone Interface in Rotator Cuff Repair

The globally prevalent rotator cuff tear has a high re-rupture rate, attributing to the failure to reproduce the interfacial fibrocartilaginous enthesis. Herein, a hierarchically organized membrane is developed that mimics the heterogeneous anatomy and properties of the natural enthesis and finely facilitates the reconstruction of tendon-bone interface. A biphasic membrane consisting of a microporous layer and a mineralized fibrous layer is constructed through the non-solvent induced phase separation (NIPS) strategy followed by a co-axial electrospinning procedure. Cationic kartogenin (KGN)-conjugated nanogel (nGel-KGN) and osteo-promotive struvite are incorporated within the membranes in a region-specific manner. During in vivo repair, the nGel-KGN-functionalized microporous layer is adjacent to the tendon which intends to suppress scar tissue formation at the lesion and simultaneously heightens chondrogenesis. Meanwhile, the struvite-containing fibrous layer covers the tubercula minus to enhance stem cell aggregation and bony ingrowth. Such tissue-specific features and spatiotemporal release behaviors contribute to effective guidance of specific defect-healing events at the transitional region, further leading to the remarkably promoted regenerative outcome in terms of the fibrocartilaginous tissue formation, collagen fiber alignment, and optimized functional motion of rotator cuff. These findings render a novel biomimetic membrane as a promising material for clinical rotator cuff repair.

Implantable Dental Barrier Membranes as Regenerative Medicine in Dentistry: A Comprehensive Review

BACKGROUND

Periodontitis and bone loss in the maxillofacial and dental areas pose considerable challenges for both functional and aesthetic outcomes. To date, implantable dental barrier membranes, designed to prevent epithelial migration into defects and create a favorable environment for targeted cells, have garnered significant interest from researchers. Consequently, a variety of materials and fabrication methods have been explored in extensive research on regenerative dental barrier membranes.

METHODS

This review focuses on dental barrier membranes, summarizing the various biomaterials used in membrane manufacturing, fabrication methods, and state-of-the-art applications for dental tissue regeneration. Based on a discussion of the pros and cons of current membrane strategies, future research directions for improved membrane designs are proposed.

RESULTS AND CONCLUSION

To endow dental membranes with various biological properties that accommodate different clinical situations, numerous biomaterials and manufacturing methods have been proposed. These approaches provide theoretical support and hold promise for advancements in dental tissue regeneration.

Effects of Nanoscale precipitates on mechanical properties, corrosion resistance, and biocompatibility in Zn-Mn alloy

Controlling degradation rate is essential for the biomedical application of biodegradable Zn alloys. Alloying with soluble elements is an effective way to regulate formation of second phases, which differ in potential from the Zn matrix. The potential difference exhibits positive or negative effects on corrosion resistance. This study successfully forms MnZn13 phase with nano size by altering ECAP temperature. Subsequently, MnZn13 phase promotes grain refinement, improvement of elongation, and corrosion resistance. Higher elongation in Zn-Mn alloy with MnZn13 phase is attributed to the grain boundary sliding, deformation twins in MnZn13 phase. Meanwhile, grain boundary corrosion in Zn-Mn alloy with MnZn13 phase is incomplete. Corrosion mode of Zn-Mn alloys without MnZn13 phase is dominated by grain boundary corrosion, accompanied by pitting corrosion. The increased corrosion resistance from MnZn13 phase stems from its higher potential than Zn matrix. Zn-Mn alloys with and without MnZn13 phase show a comparable cytocompatibility and osteogenic properties. Our findings provide an effective way to regulating mechanical properties and corrosion resistance of Zn alloys via controlling precipitation.

Chitosan and ibuprofen grafted electrospun polylactic acid/gelatin membrane mitigates inflammatory response

Electrospun membranes with biomimetic fibrous structures and high specific surfaces benefit cell proliferation and tissue regeneration but are prone to cause chronic inflammation and foreign body response. To solve these problems, we herein report an approach to functionalize electrospun membranes with antibacterial and anti-inflammatory components to modulate inflammatory responses and improve implantation outcomes. Specifically, electrospun polylactic acid (PLA)/gelatin (Gel) fibers were grafted with chitosan (CS) and ibuprofen (IBU) via carbodiimide chemistry. Our results show that the surface modification strategy endows electrospun membranes with moderate antibacterial activities and sustained release of anti-inflammatory drugs. The electrospun PLA/Gel-CS-IBU membrane showed good antioxidant and anti-inflammatory activity as evidenced by suppressing M1 polarization and promoting M2 polarization of macrophagesin vitro. Similarly, it induced significantly milder chronic inflammatory responsesin vivothan unmodified electrospun membranes. Given the good anti-inflammatory and antibacterial effects, this strategy might improve the biological performance of electrospun membranes as implants in clinics.

Nanosystems for modulation of immune responses in periodontal therapy: a mini-review

Periodontitis is one of the most common oral diseases. It is generally treated by non-surgical and/or surgical therapy with adjunctive approaches for prevention and control. The current understanding of the pathogenesis of periodontitis has unraveled the importance of the inflammatory and immune reactions to combat periodontitis whose etiology is an overlap of microbial, genetic, and environmental factors in a susceptible host. Based on this premise, many therapeutic modalities have been investigated or attempted to resolve this inflammatory disease. Amongst these, nanomedicine has been shown to have therapeutic applications in periodontitis, especially focused on immunomodulation because periodontitis is characterized by over-reactive immune response. This mini-review explores the potential of nanosystems in treating periodontitis by providing an overview of the research efforts in this field of therapeutics. The unique physicochemical and targeting properties of nanosystems seem to be potentially effective platforms for treating periodontitis.

Soft and Hard Tissue Stability Following Guided Bone Regeneration in an Active Orthodontics Patient

Guided bone regeneration (GBR) is a bone augmentation technique widely used in clinical practice to promote new bone growth by creating a conducive environment through bone grafts and barrier membranes. This article reports a case of a 14-year-old patient with significant bone loss, wound breakdown, and gingival recession in the anterior maxillary tooth, which was successfully treated through GBR combined with orthodontic treatment. This complex case of an area with bone defect required a multidisciplinary treatment in order to provide the best treatment for young patients.

Bioactive glass suspension hydrogel promotes wound healing by modulating fibroblasts

The irritation and adhesion of wound healing biomaterials to wet wounds should be addressed for achieving effective wound healing. In this study, a stable multifunctional hydrogels (BGs/HA suspension gels) were prepared using superfine powder of bioactive glasses (BGs), the biocompatible materials hyaluronic acid (HA) and carbomer940, which had good adhesion and low irritation properties for use in moist complex wounds. The average particle size of BGs/HA suspension gels was 13.11 ± 0.29μm, and the BG content was 15.8 ± 0.2% (m m-1). The results of cell proliferation, cell migration, and immunofluorescence staining experiments showed that in the initial stage of wound healing, the ionic extract of BGs formulations promoted the proliferation and migration of L929 cells and induced the secretion ofα-SMA and collagen I. In the final stage of repair, the ionic extract of the BGs formulation regulated the differentiation of fibroblast, which contributed to the reduction of pathological scar formation.In vivoexperiments showed that the wound healing rate of BGs/HA suspension gels group exceeded higher than that of the conventional BGs superfine powder group. Although BGs/HA suspension gels were comparable to its commercially available counterpart (Dermlin paste) in promoting wound healing, it addressed the problem of localized irritation caused by the high pH and low adhesion of BGs products. This study confirmed the specific regulatory effect of BGs/HA suspension gels on L929 cells, which provided a reference for the clinical application of BGs in wound dressing.

Highly plastic Zn-0.3Ca alloy for guided bone regeneration membrane: Breaking the trade-off between antibacterial ability and biocompatibility

A common problem for Zn alloys is the trade-off between antibacterial ability and biocompatibility. This paper proposes a strategy to solve this problem by increasing release ratio of Ca2+ ions, which is realized by significant refinement of CaZn13 particles through bottom circulating water-cooled casting (BCWC) and rolling. Compared with conventionally fabricated Zn-0.3Ca alloy, the BCWC-rolled alloy shows higher antibacterial abilities against E. coli and S. aureus, meanwhile much less toxicity to MC3T3-E1 cells. Additionally, plasticity, degradation uniformity, and ability to induce osteogenic differentiation in vitro of the alloy are improved. The elongation up to 49 %, which is the highest among Zn alloys with Ca, and is achieved since the sizes of CaZn13 particles and Zn grains are small and close. As a result, the long-standing problem of low formability of Zn alloys containing Ca has also been solved due to the elimination of large CaZn13 particles. The BCWC-rolled alloy is a promising candidate of making GBR membrane.

Electrospun nanofibrous membranes meet antibacterial nanomaterials: From preparation strategies to biomedical applications

Electrospun nanofibrous membranes (eNFMs) have been extensively developed for bio-applications due to their structural and compositional similarity to the natural extracellular matrix. However, the emergence of antibiotic resistance in bacterial infections significantly impedes the further development and applications of eNFMs. The development of antibacterial nanomaterials substantially nourishes the engineering design of antibacterial eNFMs for combating bacterial infections without relying on antibiotics. Herein, a comprehensive review of diverse fabrication techniques for incorporating antibacterial nanomaterials into eNFMs is presented, encompassing an exhaustive introduction to various nanomaterials and their bactericidal mechanisms. Furthermore, the latest achievements and breakthroughs in the application of these antibacterial eNFMs in tissue regenerative therapy, mainly focusing on skin, bone, periodontal and tendon tissues regeneration and repair, are systematically summarized and discussed. In particular, for the treatment of skin infection wounds, we highlight the antibiotic-free antibacterial therapy strategies of antibacterial eNFMs, including (i) single model therapies such as metal ion therapy, chemodynamic therapy, photothermal therapy, and photodynamic therapy; and (ii) multi-model therapies involving arbitrary combinations of these single models. Additionally, the limitations, challenges and future opportunities of antibacterial eNFMs in biomedical applications are also discussed. We anticipate that this comprehensive review will provide novel insights for the design and utilization of antibacterial eNFMs in future research.

Biliary stents for active materials and surface modification: Recent advances and future perspectives

Demand for biliary stents has expanded with the increasing incidence of biliary disease. The implantation of plastic or self-expandable metal stents can be an effective treatment for biliary strictures. However, these stents are nondegradable and prone to restenosis. Surgical removal or replacement of the nondegradable stents is necessary in cases of disease resolution or restenosis. To overcome these shortcomings, improvements were made to the materials and surfaces used for the stents. First, this paper reviews the advantages and limitations of nondegradable stents. Second, emphasis is placed on biodegradable polymer and biodegradable metal stents, along with functional coatings. This also encompasses tissue engineering & 3D-printed stents were highlighted. Finally, the future perspectives of biliary stents, including pro-epithelialization coatings, multifunctional coated stents, biodegradable shape memory stents, and 4D bioprinting, were discussed.

Composite superplastic aerogel scaffolds containing dopamine and bioactive glass-based fibers for skin and bone tissue regeneration

Multifunctional bioactive biomaterials with integrated bone and soft tissue regenerability hold great promise for the regeneration of trauma-affected skin and bone defects. The aim of this research was to fabricate aerogel scaffolds (GD-BF) by blending the appropriate proportions of short bioactive glass fiber (BGF), gelatin (Gel), and dopamine (DA). Electrospun polyvinyl pyrrolidone (PVP)-BGF fibers were converted into short BGF through calcination and homogenization. Microporous GD-BF scaffolds displayed good elastic deformation recovery and promoted neo-tissue formation. The DA could enable thermal crosslinking and enhance the mechanical properties and structural stability of the GD-BF scaffolds. The BGF-mediated release of therapeutic ions shorten hemostatic time (<30 s) in a rat tail amputation model and a rabbit artery injury model alongside inducing the regeneration of skin appendages (e.g., blood vessels, glands, etc.) in a full-thickness excisional defect model in rats (percentage wound closure: GD-BF2, 98 % vs. control group, 83 %) at day 14 in vitro. Taken together, these aerogel scaffolds may have significant promise for soft and hard tissue repair, which may also be worthy for the other related disciplines.

Polycaprolactone/gelatin/ZIF-8 nanofiber membrane for advanced guided tissue regeneration in periodontal therapy

The periodontal tissue regeneration strategy based on guided tissue regeneration (GTR) membranes is an effective therapy for periodontal defects. Traditional GTR membranes, however, primarily serve as physical barriers and lack antimicrobial and osteogenic functions. Herein, we developed a multifunctional nanofiber membrane with zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs) loaded in a hydrophilic gelatin layer. The release of Zn2+ from the ZIF-8 NPs effectively promoted bone tissue repair and simultaneously enabled GTR membranes with >99 % antibacterial efficacies against Escherichia coli and Staphylococcus aureus. Additionally, the incorporation of gelatin enhances cellular adhesion and growth. Furthermore, in vivo studies revealed significant bone regeneration, with increased trabecular number and reduced separation. Owing to its multiple functions, excellent biocompatibility and desirable mechanical properties, this membrane has considerable potential in the field of periodontal therapy.

Hierarchical Chitin Nanocrystal-Based 3D Printed Dual-Layer Membranes Hydrogels: A Dual Drug Delivery Nano-Platform for Periodontal Tissue Regeneration

Periodontitis, a prevalent chronic inflammatory disease caused by bacteria, poses a significant challenge to current treatments by merely slowing their progression. Herein, we propose an innovative solution in the form of hierarchical nanostructured 3D printed bilayer membranes that serve as dual-drug delivery nanoplatforms and provide scaffold function for the regeneration of periodontal tissue. Nanocomposite hydrogels were prepared by combining lipid nanoparticle-loaded grape seed extract and simvastatin, as well as chitin nanocrystals, which were then 3D printed into a bilayer membrane that possesses antimicrobial properties and multiscale porosity for periodontal tissue regeneration. The constructs exhibited excellent mechanical properties by adding chitin nanocrystals and provided a sustained release of distinct drugs over 24 days. We demonstrated that the bilayer membranes are cytocompatible and have the ability to induce bone-forming markers in human mesenchymal stem cells, while showing potent antibacterial activity against pathogens associated with periodontitis. In vivo studies further confirmed the efficacy of bilayer membranes in enhancing alveolar bone regeneration and reducing inflammation in a periodontal defect model. This approach suggests promising avenues for the development of implantable constructs that not only combat infections, but also promote the regeneration of periodontal tissue, providing valuable insights into advanced periodontitis treatment strategies.

In situ MgO nanoparticle-doped Janus electrospun dressing against bacterial invasion and immune imbalance for irregular wound healing

Owing to the unpredictable size of wounds and irregular edges formed by trauma, nanofibers' highly customizable and adherent in situ deposition can contribute to intervention in the healing process. However, electrospinning is limited by the constraints of conventional polymeric materials despite its potential for anti-inflammatory and antimicrobial properties. Here, inspired by the Janus structure and biochemistry of nanometal ions, we developed an in situ sprayed electrospinning method to overcome bacterial infections and immune imbalances during wound healing. The bilayer fiber scaffold has a hydrophobic outer layer composed of polycaprolactone (PCL) and a hydrophilic inner layer composed of gelatin, poly(L-lactic acid) (PLLA), and magnesium oxide nanoparticles, constituting the PCL/PLLA-gelatin-MgO (PPGM) electrospun scaffold. This electrospun scaffold blocked the colonization and growth of bacteria and remained stable on the wound for continuous anti-inflammatory properties to promote wound healing. Furthermore, PPGM electrospinning modulated collagen deposition and the inflammatory microenvironment in the full-thickness skin model, significantly accelerating vascularization and epithelialization progression. This personalized Janus electrospun scaffold has excellent potential as a new type of wound dressing for first aid and wound healthcare.

Methacrylated Carboxymethyl Chitosan Scaffold Containing Icariin-Loaded Short Fibers for Antibacterial, Hemostasis, and Bone Regeneration

Bone defects typically result in bone nonunion, delayed or nonhealing, and localized dysfunction, and commonly used clinical treatments (i.e., autologous and allogeneic grafts) have limited results. The multifunctional bone tissue engineering scaffold provides a new treatment for the repair of bone defects. Herein, a three-dimensional porous composite scaffold with stable mechanical support, effective antibacterial and hemostasis properties, and the ability to promote the rapid repair of bone defects was synthesized using methacrylated carboxymethyl chitosan and icariin-loaded poly-l-lactide/gelatin short fibers (M-CMCS-SFs). Icariin-loaded SFs in the M-CMCS scaffold resulted in the sustained release of osteogenic agents, which was beneficial for mechanical reinforcement. Both the porous structure and the use of chitosan facilitate the effective absorption of blood and fluid exudates. Moreover, its superior antibacterial properties could prevent the occurrence of inflammation and infection. When cultured with bone mesenchymal stem cells, the composite scaffold showed a promotion in osteogenic differentiation. Taken together, such a multifunctional composite scaffold showed comprehensive performance in antibacterial, hemostasis, and bone regeneration, thus holding promising potential in the repair of bone defects and related medical treatments.

Fabrication of Bioresorbable Barrier Membranes from Gelatin/Poly(4-Hydroxybutyrate) (P4HB)

Dental implant surgery is a procedure that replaces damaged or missing teeth with an artificial implant. During this procedure, guided bone regeneration (GBR) membranes are commonly used to inhibit the migration of epithelium and GBR at the surgical sites. Due to its biodegradability, good biocompatibility, and unique biological properties, gelatin (GT) is considered a suitable candidate for guiding periodontal tissue regeneration. However, GT-based membranes come with limitations, such as poor mechanical strength and mismatched degradation rates. To confront this challenge, a series of GT/poly(4-hydroxybutyrate) (P4HB) composite membranes are fabricated through electrospinning technology. The morphology, composition, wetting properties, mechanical properties, biocompatibility, and in vivo biodegradability of the as-prepared composite membranes are carefully characterized. The results demonstrate that all the membranes present excellent biocompatibility. Moreover, the in vivo degradation rate of the membranes can be manipulated by changing the ratio of GT and P4HB. The results indicate that the optimized GT/P4HB membranes with a high P4HB content (75%) may be suitable for periodontal tissue engineering because of their good mechanical properties and biodegradation rate compatible with tissue growth.

Nanoparticles in Periodontitis Therapy: A Review of the Current Situation

Periodontitis is a disease of inflammation that affects the tissues supporting the periodontium. It is triggered by an immunological reaction of the gums to plaque, which leads to the destruction of periodontal attachment structures. Periodontitis is one of the most commonly recognized dental disorders in the world and a major factor in the loss of adult teeth. Scaling and root planing remain crucial for managing patients with persistent periodontitis. Nevertheless, exclusive reliance on mechanical interventions like periodontal surgery, extractions, and root planning is insufficient to halt the progression of periodontitis. In response to the problem of bacterial resistance, some researchers are committed to finding alternative therapies to antibiotics. In addition, some scholars focus on finding new materials to provide a powerful microenvironment for periodontal tissue regeneration and promote osteogenic repair. Nanoparticles possess distinct therapeutic qualities, including exceptional antibacterial, anti-inflammatory, and antioxidant properties, immunomodulatory capacities, and the promotion of bone regeneration ability, which made them can be used for the treatment of periodontitis. However, there are many problems that limit the clinical translation of nanoparticles, such as toxic accumulation in cells, poor correlation between in vitro and in vivo, and poor animal-to-human transmissibility. In this paper, we review the present researches on nanoparticles in periodontitis treatment from the perspective of three main categories: inorganic nanoparticles, organic nanoparticles, and nanocomposites (including nanofibers, hydrogels, and membranes). The aim of this review is to provide a comprehensive and recent update on nanoparticles-based therapies for periodontitis. The conclusion section summarizes the opportunities and challenges in the design and clinical translation of nanoparticles for the treatment of periodontitis.

Multifunctional bilayer nanofibrous membrane enhances periodontal regeneration via mesenchymal stem cell recruitment and macrophage polarization

The continuous stimulation of periodontitis leads to a decrease in the number of stem cells within the lesion area and significantly impairing their regenerative capacity. Therefore, it is crucial to promote stem cell homing and regulate the local immune microenvironment to suppress inflammation for the regeneration of periodontitis-related tissue defects. Here, we fabricated a novel multifunctional bilayer nanofibrous membrane using electrospinning technology. The dense poly(caprolactone) (PCL) nanofibers served as the barrier layer to resist epithelial invasion, while the polyvinyl alcohol/chitooligosaccharides (PVA/COS) composite nanofiber membrane loaded with calcium beta-hydroxy-beta-methylbutyrate (HMB-Ca) acted as the functional layer. Material characterization tests revealed that the bilayer nanofibrous membrane presented desirable mechanical strength, stability, and excellent cytocompatibility. In vitro, PCL@PVA/COS/HMB-Ca (P@PCH) can not only directly promote rBMSCs migration and differentiation, but also induce macrophage toward pro-healing (M2) phenotype-polarization with increasing the secretion of anti-inflammatory and pro-healing cytokines, thus providing a favorable osteoimmune environment for stem cells recruitment and osteogenic differentiation. In vivo, the P@PCH membrane effectively recruited host MSCs to the defect area, alleviated inflammatory infiltration, and accelerated bone defects repair. Collectively, our data indicated that the P@PCH nanocomposite membrane might be a promising biomaterial candidate for guided tissue regeneration in periodontal applications.

Injectable and high-strength PLGA/CPC loaded ALN/MgO bone cement for bone regeneration by facilitating osteogenesis and inhibiting osteoclastogenesis in osteoporotic bone defects

Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to the imbalance between osteogenesis and osteoclastogenesis, making osteoporotic bone defects healing a significant clinical challenge. Calcium phosphate cement (CPC) is a promising bone substitute material due to its good osteoinductive activity, however, the drawbacks such as fragility, slow degradation rate and incapability to control bone loss restrict its application in osteoporotic bone defects treatment. Currently, we developed the PLGA electrospun nanofiber sheets to carry alendronate (ALN) and magnesium oxide nanoparticle (nMgO) into CPC, therefore, to obtain a high-strength bone cement (C/AM-PL/C). The C/AM-PL/C bone cement had high mechanical strength, anti-washout ability, good injection performance and drug sustained release capacity. More importantly, the C/AM-PL/C cement promoted the osteogenic differentiation of bone marrow mesenchymal stem cells and neovascularization via the release of Mg2+ (from nMgO) and Ca2+ (during the degradation of CPC), and inhibited osteoclastogenesis via the release of ALN in vitro. Moreover, the injection of C/AM-PL/C cement significantly improved bone healing in an OP model with femur condyle defects in vivo. Altogether, the injectable C/AM-PL/C cement could facilitate osteoporotic bone regeneration, demonstrating its capacity as a promising candidate for treatment of osteoporotic bone defects.

Zinc hybrid polyester barrier membrane accelerates guided tissue regeneration

Barrier membranes play a pivotal role in the success of guided periodontal tissue regeneration. The biodegradable barriers predominantly used in clinical practice often lack sufficient barrier strength, antibacterial properties, and bioactivity, frequently leading to suboptimal regeneration outcomes. Although with advantages in mechanical strength, biodegradability and plasticity, bioinert aliphatic polyesters as barrier materials are usually polymerized via toxic catalysts, hard to be functionalized and lack of antibacterial properties. To address these challenges, we propose a new concept that controlled release of bioactive substance on the whole degradation course can give a bioinert aliphatic polyester bioactivity. Thus, a Zn-based catalytic system for polycondensation of dicarboxylic acids and diols is created to prepare zinc covalent hybrid polyester (PBS/ZnO). The atomically-dispersed Zn2+ ions entering main chain of polyester molecules endow PBS/ZnO barrier with antibacterial properties, barrier strength, excellent biocompatibility and histocompatibility. Further studies reveal that relying on long-term controlled release of Zn2+ ions, the PBS/ZnO membrane greatly expedites osteogenetic effect in guided tissue regeneration (GTR) by enhancing the mitochondrial function of macrophages to induce M2 polarization. These findings show a novel preparation strategy of bioactive polyester biomaterials based on long term controlled release of bioactive substance that integrates catalysis, material structures and function customization.

pH-responsive, self-sculptured Mg/PLGA composite microfibers for accelerated revascularization and soft tissue regeneration

Biodegradable Mg/polymer composite fibers offer a promising therapeutic option for tissue injury because of bioactive Mg2+ and biomimetic microstructure. However, current studies are limited to the contribution of Mg2+ and the single microstructure. In this study, we designed Mg/poly (lactic-co-glycolic acid) (Mg/PLGA) composite microfibers that significantly enhanced angiogenesis and tissue regeneration synergistically by Mg2+ and self-sculptured microstructure, due to spontaneous in situ microphase separation in response to the weakly alkaline microenvironment. Our composite microfiber patch exhibited superior performance in the adhesion, spreading, and angiogenesis functions of human umbilical vein endothelial cells (HUVECs) due to the joint contribution of the hierarchically porous microstructure and Mg2+. Genomics and proteomics analyses revealed that the Mg/PLGA composite microfibers activated the cell focal adhesion and angiogenesis-related signaling pathways. Furthermore, the repair of typical soft tissue defects, including refractory urethral wounds and easily healed skin wounds, validated that our Mg/PLGA composite microfiber patch could provide favorable surface topography and ions microenvironment for tissue infiltration and accelerated revascularization. It could cause rapid urethral tissue regeneration and recovery of rabbit urethral function within 6 weeks and accelerate rat skin wound closure within 16 days. This work provides new insight into soft tissue regeneration through the bioactive alkaline substance/block copolymer composites interactions.

Addressing Antimicrobial Properties in Guided Tissue/Bone Regeneration Membrane: Enhancing Effectiveness in Periodontitis Treatment

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) are the two surgical techniques generally used for periodontitis disease treatment. These techniques are based on a barrier membrane to direct the growth of new bone and gingival tissue at sites with insufficient volumes or dimensions of bone or gingiva for proper function, esthetics, or prosthetic restoration. Numerous studies have highlighted biocompatibility, space-creation, cell-blocking, bioactivity, and proper handling as essential characteristics of a membrane's performance. Given that bacterial infection is the primary cause of periodontitis, we strongly believe that addressing the antimicrobial properties of these membranes is of utmost importance. Indeed, the absence of effective inhibition of periodontal pathogens has been recognized as a primary factor contributing to the failure of GTR/GBR membranes. Therefore, we suggest considering antimicrobial properties as one of the key factors in the design of GTR/GBR membranes. Antibiotics are potent medications frequently administered systemically to combat microbes and mitigate bacterial infections. Nevertheless, the excessive use of antibiotics has resulted in a surge in bacterial resistance. To overcome this challenge, alternative antibacterial substances have been developed. In this review, we explore the utilization of alternative substances with antimicrobial properties for topical application in membranes. The use of antibacterial nanoparticles, phytochemical compounds, and antimicrobial peptides in this context was investigated. By carefully selecting and integrating antimicrobial agents into GTR/GBR membranes, we can significantly enhance their effectiveness in combating periodontitis. These antibacterial substances not only act as barriers against pathogenic bacteria but also promote the process of periodontal healing.

Methacrylated gelatin and platelet-rich plasma based hydrogels promote regeneration of critical-sized bone defects

Physiological repair of large-sized bone defects requires instructive scaffolds with appropriate mechanical properties, biocompatibility, biodegradability, vasculogenic ability and osteo-inductivity. The objective of this study was to fabricate in situ injectable hydrogels using platelet-rich plasma (PRP)-loaded gelatin methacrylate (GM) and employ them for the regeneration of large-sized bone defects. We performed various biological assays as well as assessed the mechanical properties of GM@PRP hydrogels alongside evaluating the release kinetics of growth factors (GFs) from hydrogels. The GM@PRP hydrogels manifested sufficient mechanical properties to support the filling of the tissue defects. For biofunction assay, the GM@PRP hydrogels significantly improved cell migration and angiogenesis. Especially, transcriptome RNA sequencing of human umbilical vein endothelial cells and bone marrow-derived stem cells were performed to delineate vascularization and biomineralization abilities of GM@PRP hydrogels. The GM@PRP hydrogels were subcutaneously implanted in rats for up to 4 weeks for preliminary biocompatibility followed by their transplantation into a tibial defect model for up to 8 weeks in rats. Tibial defects treated with GM@PRP hydrogels manifested significant bone regeneration as well as angiogenesis, biomineralization, and collagen deposition. Based on the biocompatibility and biological function of GM@PRP hydrogels, a new strategy is provided for the regenerative repair of large-size bone defects.

Osteogenic Potential of Magnesium Oxide Nanoparticles in Bone Regeneration: A Systematic Review

Guided bone regeneration (GBR) plays a crucial role in the augmentation of alveolar bone, especially in cases of dental implants. The main principle behind using membranes in guided tissue regeneration (GTR) is to prevent epithelial downgrowth as well as connective tissue on the root surface. However, the membranes lack some major properties, such as osteogenic and antimicrobial properties. Magnesium (Mg) is one of the biodegradable materials that is gaining interest because of its favourable mechanical properties and biocompatibility. It also possesses pro-osteogenic properties and significant inhibition of biofilm formation and maturation. These features have attracted increasing interest in using magnesium oxide nanoparticles in GBR membrane applications. This systematic review assesses the osteogenic potential of magnesium oxide nanoparticles in periodontal bone regeneration. The literature search used PubMed, PubMed Central, Medline, and Cochrane databases to examine systematic reviews published till March 2023. Seven articles were included based on the selection criteria. We included all in vitro and in vivo clinical studies based on the osteogenic potential of magnesium oxide nanoparticles in periodontal bone regeneration. The seven studies provided evidence that magnesium oxide nanoparticles, when incorporated in any substrate, showed higher osteogenic potential in terms of higher alkaline phosphatase levels, bone volume fraction, and bone mineral density. The optimum concentration of magnesium oxide can be an ideal additive to various substrates to promote bone regeneration. Because most of the studies were conducted on calvarial defects, further studies should focus only on bone regeneration related to periodontal regeneration.

A multifunctional quercetin/polycaprolactone electrospun fibrous membrane for periodontal bone regeneration

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Improving astaxanthin-loaded chitosan/polyvinyl alcohol/graphene oxide nanofiber membranes and their application in periodontitis

Periodontitis is a chronic inflammatory disease primarily driven by host inflammation and plaque-induced immune responses. Controlling the host inflammatory response and improving the periodontal inflammatory microenvironment are crucial to promoting periodontal tissue regeneration. In this study, the blended nanofiber membranes previously prepared by our research group were improved, and we developed multifunctional chitosan/polyvinyl alcohol/graphene oxide/astaxanthin coaxial nanofiber membranes. Scanning electron microscopy showed that the prepared nanofibers had a smooth surface and a uniform diameter distribution. The mechanical property test results showed that the coaxial nanofiber membranes exhibited higher tensile strength compared to the blended nanofiber membranes, which increased from 4.50 ± 0.32 and 3.70 ± 0.45 MPa to 7.12 ± 0.22 and 5.62 ± 0.79 MPa respectively. Drug release studies indicated that the "shell-core" structure of coaxial nanofibers significantly reduced the initial burst release of astaxanthin (ASTA), with only 13.49 % and 10.71 % release in the first 24 h, and drug release lasted for over a week. Animal experiments confirmed that the coaxial nanofiber membranes loaded with ASTA promoted periodontal bone defect repair while inhibiting periodontal inflammation. In conclusion, the prepared coaxial nanofiber membranes are a promising sustained-release drug system for treating periodontitis.

Electrospun membranes chelated by metal magnesium ions enhance pro-angiogenic activity and promote diabetic wound healing

Diabetic wounds, resulting from skin atrophy due to localized ischemia and hypoxia in diabetic patients, lead to chronic pathological inflammation and delayed healing. Using electrospinning technology, we developed magnesium ion-chelated nanofiber membranes to explore their efficacy in antibacterial, anti-inflammatory, and angiogenic applications for wound healing. These membranes are flexible and elastic, resembling native skin tissue, and possess good hydrophilicity for comfortable wound bed contact. The mechanical properties of nanofiber membranes are enhanced by the chelation of magnesium ions (Mg2+), which also facilitates a long-term slow release of Mg2+. The cytocompatibility of the nanofibrous membranes is influenced by their Mg2+ content: lower levels encourage the proliferation of fibroblasts, endothelial cells, and macrophages, while higher levels are inhibitory. In a diabetic rat model, magnesium ion-chelated nanofibrous membranes effectively reduced early wound inflammation and notably accelerated wound healing. This study highlights the potential of magnesium ion-chelated nanofiber membranes in treating diabetic wounds.

Dual Mg-Reinforced PCL Membrane with a Janus Structure for Vascularized Bone Regeneration and Bacterial Elimination

Commercially available guided bone regeneration (GBR) membranes often exhibit limited mechanical properties or bioactivity, leading to poor performance in repairing bone defects. To surmount this limitation, we developed a Janus structural composite membrane (Mg-MgO/PCL) reinforced by dual Mg (Mg sheets and MgO NPs) by using a combined processing technique involving casting and electrospinning. Results showed that the addition of Mg sheets and MgO NPs enhanced the mechanical properties of the composite membrane for osteogenic space maintenance, specifically tensile strength (from 10.2 ± 1.2 to 50.3 ± 4.5 MPa) and compression force (from 0 to 0.94 ± 0.09 N mm-1), through Mg sheet reinforcement and improved crystallization. The dense cast side of the Janus structure membrane displayed better fibroblast barrier capacity than a single fiber structure; meanwhile, the PCL matrix protected the Mg sheet from severe corrosion due to predeformation. The porous microfibers side supported preosteoblast cell adhesion, enhanced osteogenesis, and angiogenesis in vitro, through the biomimetic extracellular matrix and sustainable Mg2+ release. Furthermore, the Mg-MgO/PCL membrane incorporating 2 wt % MgO NPs exhibited remarkable antimicrobial properties, inducing over 88.75% apoptosis in Staphylococcus aureus. An in vivo experiment using the rat skull defect model (Φ = 5 mm) confirmed that the Mg-MgO/PCL membrane significantly improved new bone formation postsurgery. Collectively, our investigation provides valuable insights into the design of multifunctional membranes for clinical oral GBR application.

New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Multiphasic bone-ligament-bone integrated scaffold enhances ligamentization and graft-bone integration after anterior cruciate ligament reconstruction

The escalating prevalence of anterior cruciate ligament (ACL) injuries in sports necessitates innovative strategies for ACL reconstruction. In this study, we propose a multiphasic bone-ligament-bone (BLB) integrated scaffold as a potential solution. The BLB scaffold comprised two polylactic acid (PLA)/deferoxamine (DFO)@mesoporous hydroxyapatite (MHA) thermally induced phase separation (TIPS) scaffolds bridged by silk fibroin (SF)/connective tissue growth factor (CTGF)@Poly(l-lactide-co-ε-caprolactone) (PLCL) nanofiber yarn braided scaffold. This combination mimics the native architecture of the ACL tissue. The mechanical properties of the BLB scaffolds were determined to be compatible with the human ACL. In vitro experiments demonstrated that CTGF induced the expression of ligament-related genes, while TIPS scaffolds loaded with MHA and DFO enhanced the osteogenic-related gene expression of bone marrow stem cells (BMSCs) and promoted the migration and tubular formation of human umbilical vein endothelial cells (HUVECs). In rabbit models, the BLB scaffold efficiently facilitated ligamentization and graft-bone integration processes by providing bioactive substances. The double delivery of DFO and calcium ions by the BLB scaffold synergistically promoted bone regeneration, while CTGF improved collagen formation and ligament healing. Collectively, the findings indicate that the BLB scaffold exhibits substantial promise for ACL reconstruction. Additional investigation and advancement of this scaffold may yield enhanced results in the management of ACL injuries.

Hierarchically patterned triple-layered gelatin-based electrospun membrane functionalized by cell-specific extracellular matrix for periodontal regeneration

OBJECTIVES

Regenerating the periodontium poses a critical challenge in oral medicine. To repair various periodontal defects, it is necessary to adopt a bio-scaffold that provides both the architecture and bioactive cues for local stem cells to migrate, reside, proliferate, and differentiate. The objective of this study is to combine a cell-specific decellularized extracellular matrix (ECM) and a biomimetic electrospinning scaffold to regenerate severely destructed periodontium.

METHODS

SEM, water contact angle (WCA), live/dead staining, swelling ratio, tensile test and immune-fluorescent staining were used to define the suitable topography for certain dental stem cells seeding and culturing. Transwell assay, CCK-8, Alizarin Red staining and PCR immune-fluorescent staining were used to determine ideal cell-specific ECM for PDLSCs/BMSCs migration, viability, and oriented differentiation. A biodegradable triple-layered electrospun scaffold (TLS) was fabricated by electrospinning with aligned fibers on both surfaces and a polyporous structure in the middle. The morphology and inter-porous structure of the TLS were characterized by SEM and mercury intrusion porosimetry (MIP). The surface of the TLS was functionalized with cell-specific ECM (Bi-ECM-TLS) through decellularization of the cell sheets cultured on the scaffold. The regenerative outcome of Bi-ECM-TLS was assessed by an in-situ rat periodontal defect model. Micro-CT, HE-staining, Masson's trichome staining, Sirius Red staining and Immunofluorescent staining were used for histological analysis.

RESULTS

Aligned Gelatin/PCL fibrous membrane (GPA) was most effective for both PDLSCs and BMSCs in culture with WCA around 50 degrees and better mechanical strength than the rest. MSCs favored the same type of ECM (cell-specific ECM), and their regenerative properties were effectively induced with better chemotaxis, proliferative and differentiating behaviors. TLS characterization showed that TLS possessed aligned-random-aligned structure and inter-porous structure. In a rat model of periodontal defects, the TLS functionalized by BMSC-specific ECM for bone regeneration and PDLSC-specific ECM demonstrated highest BV/TV ratio, best bone structure and ligament fiber orientation and blood vessel formation, suggesting optimal performance in regenerating both alveolar bone and periodontal ligaments over TLS, single-ECM loaded TLS and r-Bi-ECM-TLS.

SIGNIFICANCE

This study highlights the importance of combining a cell-specific decellularized ECM and a biomimetic electrospinning scaffold for targeted periodontal tissue regeneration, with potential implications for periodontal tissue engineering and improved patient outcomes.

Photothermal therapy of copper incorporated nanomaterials for biomedicine

Studies have reported on the significance of copper incorporated nanomaterials (CINMs) in cancer theranostics and tissue regeneration. Given their unique physicochemical properties and tunable nanostructures, CINMs are used in photothermal therapy (PTT) and photothermal-derived combination therapies. They have the potential to overcome the challenges of unsatisfactory efficacy of conventional therapies in an efficient and non-invasive manner. This review summarizes the recent advances in CINMs-based PTT in biomedicine. First, the classification and structure of CINMs are introduced. CINMs-based PTT combination therapy in tumors and PTT guided by multiple imaging modalities are then reviewed. Various representative designs of CINMs-based PTT in bone, skin and other organs are presented. Furthermore, the biosafety of CINMs is discussed. Finally, this analysis delves into the current challenges that researchers face and offers an optimistic outlook on the prospects of clinical translational research in this field. This review aims at elucidating on the applications of CINMs-based PTT and derived combination therapies in biomedicine to encourage future design and clinical translation.

A Fiber Sliding-Orientation Based Micromechanics Failure Model for Melt-Blown Nonwovens

The mechanical model of melt-blown nonwovens (MNs) serves as the foundation for performance optimization, which can offer helpful guidance for product material selection, structural design, and cost control. However, it is challenging to describe the micromechanics failure mechanism of MNs using the traditional mechanical model, which aims to match the model curve with the experimental result at the macrolevel. Herein, a micromechanics failure model for MNs based on sliding-orientation competition is developed. Through in situ observations of fiber position changes and the fluctuation of stress-strain curves, fiber sliding and orientation are introduced into the failure process of MNs. Due to fiber bonding and static friction, only orientation happens during the first stage of stretching. In dramatic contrast, the fibers will slide and orient in the second stage of stretching to change their positions in response to the external force. Sliding friction, fiber bonding, and static friction make up the stress of MNs, and the conflict of fiber sliding and orientation causes variations in the stress. The model has been successfully applied to polylactic acid (PLA) MNs, which proves the effectiveness of the model in MNs.

An injectable and thermosensitive hydrogel with nano-aided NIR-II phototherapeutic and chemical effects for periodontal antibacteria and bone regeneration

Periodontitis is a common public health problem worldwide and an inflammatory disease with irregular defect of alveolar bone caused by periodontal pathogens. Both antibacterial therapy and bone regeneration are of great importance in the treatment of periodontitis. In this study, injectable and thermosensitive hydrogels with 3D networks were used as carriers for controlled release of osteo-inductive agent (BMP-2) and Near Infrared Region-II (NIR-II) phototherapy agents (T8IC nano-particles). T8IC nano-particles were prepared by reprecipitation and acted as photosensitizer under 808 nm laser irradiation. Besides, we promoted photodynamic therapy (PDT) through adding H2O2 to facilitate the antibacterial effect instead of increasing the temperature of photothermal therapy (PTT). Hydrogel + T8IC + Laser + BMP-2 + H2O2 incorporated with mild PTT (45 °C), enhanced PDT and sustained release of BMP-2. It was present with excellent bactericidal effect, osteogenic induction and biosafety both in vitro and in vivo. Besides, immunohistochemistry staining and micro-CT analyses had confirmed that PTT and PDT could promote bone regeneration through alleviating inflammation state. Altogether, this novel approach with synergistic antibacterial effect, anti-inflammation and bone regeneration has a great potential for the treatment of periodontitis in the future.

Janus functional electrospun polyurethane fibrous membranes for periodontal tissue regeneration

The guided tissue regeneration (GTR) technique with GTR membranes is an efficient method for repairing periodontal defects. Conventional periodontal membranes act as physical barriers that resist the growth of fibroblasts, epithelial cells, and connective tissue. However, they cannot facilitate the regeneration of periodontal tissue. To address this issue, the exploitation of novel GTR membranes with bioactive functions based on therapeutic requirements is critical. Herein, we exploited a biodegradable bilayer polyurethane fibrous membrane by uniaxial electrostatic spinning to construct two sides with Janus properties by integrating the bioactive molecule dopamine (DA) and antimicrobial Gemini quaternary ammonium salt (QAS). The DA-containing side, located inside the injury, can effectively promote cell adhesion and mesenchymal stem cell growth as well as support mineralization and antioxidant properties, which are beneficial for bone regeneration. The QAS-containing side, located on the outer surface of the injury, endows antibacterial properties and limits fibroblast adhesion and growth on its surface owing to its strong hydrophilicity. An in vivo study demonstrates that the Janus polyurethane fibrous membrane can significantly promote the regeneration of periodontal defects in rats. Owing to its superior mechanical properties and biocompatibility, this polyurethane fibrous membrane has potential applications in the field of periodontal regeneration.

Accumulative Rolling Mg/PLLA Composite Membrane with Lamellar Heterostructure for Enhanced Bacteria Inhibition and Rapid Bone Regeneration

Developing composite materials with optimized mechanics, degradation, and bioactivity for bone regeneration has long been a crucial mission. Herein, a multifunctional Mg/Poly-l-lactic acid (Mg/PLLA) composite membrane based on the "materials plain" concept through the accumulative rolling (AR) method is proposed. Results show that at a rolling ratio of 75%, the comprehensive mechanical properties of the membrane in the rolling direction are self-reinforced significantly (elongation at break ≈53.2%, tensile strength ≈104.0 MPa, Young's modulus ≈2.13 GPa). This enhancement is attributed to the directional arrangement and increased crystallization of PLLA molecular chains, as demonstrated by SAXS and DSC results. Furthermore, the AR composite membrane presents a lamellar heterostructure, which not only avoids the accumulation of Mg microparticles (MgMPs) but also regulates the degradation rate. Through the contribution of bioactive MgMPs and their photothermal effect synergistically, the membrane effectively eliminates bacterial infection and accelerates vascularized bone regeneration both in vitro and in vivo. Notably, the membrane exhibits outstanding rat skull bone regeneration performance in only 4 weeks, surpassing most literature reports. In short, this work develops a composite membrane with a "one stone, four birds" effect, opening an efficient avenue toward high-performance orthopedic materials.

Antibacterial efficacy of epigallocatechin-3-gallate cross-linked small intestinal submucosa guided bone regeneration membrane

The leading cause of guided bone regeneration (GBR) failure is infection. Herein, we developed a new GBR membrane with good mechanical and osteogenic properties by crosslinking the small intestinal submucosa (SIS) with epigallocatechin-3-gallate (EGCG). Meanwhile, EGCG is also a natural antibacterial agent. This study aimed to investigate the antibacterial efficacy of EGCG-crosslinked SIS (E-SIS) against Staphylococcus aureus and Escherichia coli through EGCG release, bacterial count, live/dead staining, scanning electron microscopy, growth curve, and biofilm formation tests. The results showed that E-SIS effectively inhibited bacteria's growth and adhesion, and its antibacterial activity against Staphylococcus aureus was stronger than that against Escherichia coli. 0.5% E-SIS had the most potent antibacterial activity. The antibacterial mechanism of E-SIS might be related to the release of EGCG and the surface properties of E-SIS. In conclusion, 0.5% E-SIS is a promising GBR membrane with good osteogenic and antibacterial properties.

Biodegradability of Amniotic Membrane as Potential Scaffold for Periodontal Regeneration

Background In the periodontal regenerative procedure, the membrane used should possess good mechanical stability with suitable resorption time to allow restoration of the lost periodontium. Amniotic membrane (AM) has regenerative potential as a scaffold or barrier membrane due to its various beneficial properties. However, its degradation rate is not clearly reported. Methodology This study aimed to evaluate the resorption capacity of AM and its surface architecture after being subjected to hydrolytic degradation analysis in phosphate buffer solution (PBS). AM was cut into sizes of 10 × 10 mm2 for three replicates. The membranes were weighed before and at different time intervals (days 7, 14, 21, and 28) after immersion in PBS. The degradation rate was determined by the percentage of mean weight loss from the initial weight at different time intervals. The AM surface profile was observed under scanning electron microscopy (SEM) before and after 28 days of immersion. Results The result shows a 92% loss of weight over 28 days with the highest attained in the first seven days (67%), followed by 7%, 17%, and 1% after days 14, 21, and 28, respectively. SEM of the AM surface before the degradation test showed a polygonal shape forming a well-arranged mosaic pattern covered with microvilli. At day 28, the remaining AM appears as porous surface architecture, irregularly arranged fibers, and no microvilli seen. Conclusions This study demonstrated that over four weeks of degradation analysis, AM was not entirely degraded but had lost some of the microstructure. The biodegradability of AM should be further evaluated to elucidate its stability within adequate time parallel with the tissue healing process in periodontal tissue regeneration.

Rational Designs of Biomaterials for Combating Oral Biofilm Infections

Oral biofilms, which are also known as dental plaque, are the culprit of a wide range of oral diseases and systemic diseases, thus contributing to serious health risks. The manner of how to achieve good control of oral biofilms has been an increasing public concern. Novel antimicrobial biomaterials with highly controllable fabrication and functionalization have been proven to be promising candidates. However, previous reviews have generally emphasized the physicochemical properties, action mode, and application effectiveness of those biomaterials, whereas insufficient attention has been given to the design rationales tailored to different infection types and application scenarios. To offer guidance for better diversification and functionalization of anti-oral-biofilm biomaterials, this review details the up-to-date design rationales in three aspects: the core strategies in combating oral biofilm, as well as the biomaterials with advanced antibiofilm capacity and multiple functions based on the improvement or combination of the abovementioned antimicrobial strategies. Thereafter, insights on the existing challenges and future improvement of biomaterial-assisted oral biofilm treatments are proposed, hoping to provide a theoretical basis and reference for the subsequent design and application of antibiofilm biomaterials.

Recent Advances on Electrospun Nanofibers for Periodontal Regeneration

Periodontitis is an inflammatory infection caused by bacterial plaque accumulation that affects the periodontal tissues. Current treatments lack bioactive signals to induce tissue repair and coordinated regeneration of the periodontium, thus alternative strategies are needed to improve clinical outcomes. Electrospun nanofibers present high porosity and surface area and are able to mimic the natural extracellular matrix, which modulates cell attachment, migration, proliferation, and differentiation. Recently, several electrospun nanofibrous membranes have been fabricated with antibacterial, anti-inflammatory, and osteogenic properties, showing promising results for periodontal regeneration. Thus, this review aims to provide an overview of the current state of the art of these nanofibrous scaffolds in periodontal regeneration strategies. First, we describe the periodontal tissues and periodontitis, as well as the currently available treatments. Next, periodontal tissue engineering (TE) strategies, as promising alternatives to the current treatments, are addressed. Electrospinning is briefly explained, the characteristics of electrospun nanofibrous scaffolds are highlighted, and a detailed overview of electrospun nanofibers applied to periodontal TE is provided. Finally, current limitations and possible future developments of electrospun nanofibrous scaffolds for periodontitis treatment are also discussed.