Biomimetic hydroxyapate/polydopamine composites with good biocompatibility and efficiency for uncontrolled bleeding

A multifunctional gingival retraction cord with antibacterial and hemostasis properties based on Chitosan/Propolis/Tranexamic acid for dental treatment

A novel gingival retraction cord named P/TA@CSy was prepared using chitosan yarns (CSy) loaded with tranexamic acid (TA) and Propolis (P). P/TA@CSy has good toughness with a breaking strength of 41.3 Pa, benefiting from the twisting structure and Propolis coating. A short coagulation time of 456 s was achieved for P/TA@CSy because of the potent blood absorption ability from the effective attachment of tranexamic acid. Moreover, excellent antibacterial ability was obtained with the antibacterial rates against E. coli of 94.73 %, S. aureus of 99.99 % and S. mutans of 99.99 %, contributing to Propolis's antibacterial ability. In addition, suppression of the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was found, which could prevent wound infection. P/TA@CSy displayed excellent cytocompatibility with the cell activity of 100 % after 24 h. Therefore, P/TA@CSy could rapidly respond to gingival hemostasis and infection prevention, showing excellent potential in dental treatment.

A Bilayer Polyurethane Patch with Sustained Growth Factor Release and Antibacteria for Re-epithelization of Large-Scale Oral Mucosal Defects

In the field of oral and maxillofacial surgery, extensive oral soft-tissue injuries occur repeatedly in clinical practice; however, effective restorative materials are lacking. In this study, a biodegradable waterborne polyurethane patch featuring a mucosa bionic bilayer structure is presented. This patch consists of a porous scaffold layer that faces the lesion, incorporating a polydopamine coating to achieve sustained release of epidermal growth factors (EGFs) for mucosal defect reconstruction. Additionally, there is a dense barrier layer toward the oral cavity loaded with silver nanoparticles, which prevents bacteria from entering the wound and simultaneously acts as a physical barrier. This patch can sustainably release EGF in vitro for 2 weeks, thereby facilitating the proliferation and migration of HaCaT and L929 cells, while effectively killing common oral cavity bacteria. In a rabbit buccal mucosal full-thickness defect model, the patch demonstrates better efficacy than the clinical benchmark, decellularized extracellular matrix (dECM). It effectively reduces wound inflammation and significantly upregulates gene expression associated with epithelialization by activating the EGF/epidermal growth factor receptor (EGFR) pathway. These mechanisms promote the proliferation, differentiation, and migration of epithelial/keratinocyte cells, ultimately expediting mucosal defect healing and wound closure.

Robust adhesive nanocomposite sponge composed of citric acid and nano clays modified cellulose for rapid hemostasis of lethal non-compressible hemorrhage

Massive bleeding control plays the main role in saving people's lives in emergency situations. Herein, modified cellulose-based nanocomposite sponges by polydopamine (PDA) and laponite nano-clay was developed to sturdily deal with non-compressible lethal severe bleeding. PDA accomplishes supreme adhesion in the bleeding site (∼405 kPa) to form strong physical barrier and seal the position. Sponges super porous (∼70 % porosity) and super absorbent capacity (48 g blood absorbed per 1 g sponge) by concentrating the blood cells and platelets provides the requirements for primary hemostasis. Synergistically, the nanocomposite sponges' intelligent chemical structure induces hemostasis by activation of the XI, IX, X, II and FVII factors of intrinsic and extrinsic coagulation pathways. Excellent hemostatic performance of sponges in-vitro was assessed by RBC accumulation (∼100 %), blood clotting index (∼10 %), platelet aggregation/activation (∼93 %) and clotting time. The nanocomposite sponges depicted super performance in the fatal high-pressure non-compressible hemorrhage model by reducing of >2, 15 and 3 times in the bleeding amount at New Zealand rabbit's heart and liver, and rat's femoral artery bleeding models, respectively compared to commercial hemostatic agents (Pvalue˂0.001). The in-vivo host response results exhibited biosafety with no systemic and significant local inflammatory response by hematological, pathological and biochemical parameters assessments.

Recent Development and Applications of Polydopamine in Tissue Repair and Regeneration Biomaterials

The various tissue damages are a severe problem to human health. The limited human tissue regenerate ability requires suitable biomaterials to help damage tissue repair and regeneration. Therefore, many researchers devoted themselves to exploring biomaterials suitable for tissue repair and regeneration. Polydopamine (PDA) as a natural and multifunctional material which is inspired by mussel has been widely applied in different biomaterials. The excellent properties of PDA, such as strong adhesion, photothermal and high drug-loaded capacity, seem to be born for tissue repair and regeneration. Furthermore, PDA combined with different materials can exert unexpected effects. Thus, to inspire researchers, this review summarizes the recent and representative development of PDA biomaterials in tissue repair and regeneration. This article focuses on why apply PDA in these biomaterials and what PDA can do in different tissue injuries.

A quaternized chitosan and carboxylated cellulose nanofiber-based sponge with a microchannel structure for rapid hemostasis and wound healing

A hemostatic sponge should perform rapid hemostasis and exhibit antibacterial properties, whilst being non-toxic, breathable, and degradable. This study prepared a hemostatic sponge (CQTC) with microchannels, specifically a microchannel structure based on quaternized chitosan (QCS) and carboxylated cellulose nanofibers (CCNF) obtained by using tannic acid and Cu²⁺ complex (crosslinking agent). The sponge had low density and high porosity, while being degradable. The combination of microchannels and three-dimensional porous structure of CQTC leads to excellent liquid absorption and hemostasis ability, based on a liquid absorption rate test and in vitro hemostasis experiment. In addition, CQTC exhibited excellent antibacterial activity against both gram-negative and gram-positive bacteria, and it promoted wound healing. In conclusion, this porous and microchannel hemostatic sponge has broad application prospects as a clinical wound hemostatic material.

Polydopamine constructed interfacial molecular bridge in nano-hydroxylapatite/polycaprolactone composite scaffold

Nano-hydroxylapatite (nano-HAP)/polycaprolactone (PCL) composite scaffold is proved to possess great potential for bone tissue engineering application since the biocompatibility of PCL and the osteoinduction ability of nano-HAP. However, the interfacial bonding between nano-HAP and PCL is weak by reason of the difference in thermodynamic properties. Herein, nano-HAP was modified by polydopamine (PDA) and then added to the PCL matrix to enhance their interface bonding in bone scaffold manufactured by selective laser sintering (SLS). The results indicated that PDA acted as an interfacial molecular bridge between PCL and nano-HAP. On one hand, the amino groups of PDA formed hydrogen bonding with the hydroxyl groups of nano-HAP, and on the other hand, the catechol groups of PDA formed hydrogen bonding with the ester groups of PCL. Compared with the HAP/PCL scaffolds, the tensile and compressive strength of the P-HAP/PCL scaffolds loading 12 wt% P-HAP were increased by 10% and 16%, respectively. Meanwhile, the scaffold possessed great bioactivity and cytocompatibility that could accelerate the formation of apatite layers and promote the cell adhesion, proliferation and differentiation.

Mussel-inspired collagen-hyaluronic acid composite scaffold with excellent antioxidant properties and sustained release of a growth factor for enhancing diabetic wound healing

Long-term non-healing diabetic wounds are always a serious challenge and a global healthcare burden that needs to be resolved urgently in the clinic. Prolonged inflammation and impaired angiogenesis are the main direct causes of diabetic wounds. With the development of polymer biomaterials, various wound dressings have been created, but a few of them have been applied to the clinical management of diabetic wounds. Here, we developed a mussel-inspired bioactive scaffold consisting mainly of collagen and hyaluronic acid, which are natural biopolymer materials contained in human tissues. First, we fabricated different polydopamine modified lyophilized collagen hyaluronic acid scaffolds under different concentrations of dopamine alkaline solutions, 0.5, 1, 2 ​mg/mL, so named CHS-PDA-0.5, CHS-PDA-1, CHS-PDA-2. After testing their physical and chemical properties, antioxidant effect, inflammation regulation, as well as drug loading and release capabilities, we obtained a bioactive endothelial growth factor (EGF)-loaded wound dressing, CHS-PDA-2@EGF, which can resist reactive oxygen species (ROS) and promote the regeneration of chronic wounds in diabetic rats by reducing inflammation. In addition, the scaffold showed excellent swelling ability, a certain coagulation effect and reasonable degradation. Therefore, the scaffold has great potential to be used in clinical diabetic wound treatment as a low-cost and easily available wound dressing to accelerate chronic wound healing.