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Guided bone regeneration (GBR) is currently the most widely used bone augmentation technique in oral clinics. However, infection and soft tissue management remain the greatest challenge. In this study, a Janus sponge/electrospun fibre membrane containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and chlorhexidine (CHX) were prepared to optimize its application as a barrier membrane for GBR. The loose sponge part was covalently bonded with the fiber part which has a dense structure. The composed scaffold exhibited superior biocompatibility and antibacterial activity verified by in vitro test. A rat model of unilateral skull bone injury was used to confirm the effectiveness on both hard and soft tissue regeneration. The chitosan sponge on the soft tissue side containing EGF, bFGF and CHX had a loose structure, promoting collagen and cell regeneration and exerting an antibacterial effect. Meanwhile, the dense PLGA/PCL layer on the hard tissue side prevented fibroblast entry into the bone defect, thereby facilitating bone regeneration. The Janus composite scaffold provides a promising strategy for oral tissue restoration. [Display omitted] • A Janus fibre/sponge composite combining EGF, bFGF and CHX was successfully fabricated for oral guided tissue regeneration. • The composite had a Janus structure and showed superior antimicrobial ability. • The composite can work as barrier membrane to screen the fibroblast, as well as a scaffold to promote bone regeneration. [ABSTRACT FROM AUTHOR]

In this work, a novel application of whey protein isolate (WPI) for surface coating of magnetic nanoparticles (MNPs) is demonstrated. WPI-modified MNPs (WPI-MNPs) were prepared via chemical co-precipitation of ferrous and ferric salts. A mixture of chitosan and MNPs (or WPI-MNPs) was subject to lyophilization to produce magnetic composite sponges (designated as Chi-MNPs, and Chi-WPI-MNPs, respectively). Scanning electron microscopy (SEM) images clearly show improvement in dispersibility of WPI-MNPs on Chi-WPI-MNPs compared to the uncoated samples. The saturation magnetization profiles of all MNP samples, which were measured by a vibrating sample magnetometer (VSM), show superparamagnetic properties. The pore structure determined by mercury intrusion porosimeter (MIP) reveals a larger average pore size for Chi-WPI-MNPs compared to Chi-MNPs. The percentages for methylene blue (MB) dye removal of Chi-WPI-MNPs increased by 23.3% and 12.7% when compared to those of neat and Chi-MNPs sponges, respectively. The adsorption isotherms of all sponges can be described by both Langmuir and Freundlich models. The sponge containing WPI-MNPs could be reused with a 23.7% reduction in adsorption efficiency after 4 cycles of use. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hardwood vessel-inspired chitosan-based sponge was prepared. • The sponge showed superior strength, MPs adsorption and recycling durability. • Strength was enhanced by double cross-linked network and biomimetic structure. • MPs adsorption efficiency was increased due to the biomimetic structure. • Adsorption mechanism of sponge was analyzed and discussed in this work. Microplastics (MPs) in water that are hazardous and recalcitrant pose formidable risks for human health, necessitating the development of efficient, sustainable removal methods. This study introduces a chitosan/bacterial cellulose sponge with superior compressibility and remarkable recyclability for polystyrene (PS) MPs rapid adsorption, inspired by the robustness and directional, rapid nutrient transport characteristics of hardwood vessels. The unique structure of sponge, featuring tunable oriented cellular channels and strong walls, is achieved via temperature-controlled directional freezing and double cross-linking. This structure enables the sponge to maintain high wet compressive reversibility, with a retention rate of 94.9% after 100 compression cycles. Moreover, the as-prepared sponge demonstrates a high MPs adsorption capacity of 0.26 mg·g−1. Owing to its excellent wet compressibility and adsorption performance, the sponge demonstrates remarkable cycling removal efficiency of 47.30% after 20 cycles. The experimental results together with theoretical fitting provide insight into how the hardwood-like structure and active sites of Chitosan enhance MPs adsorption. This work advances the development of efficient and sustainable MPs removal technologies using biomimetic and high-performance adsorbents and expands the insight into the MPs adsorption mechanism by chitosan-based sponge. [ABSTRACT FROM AUTHOR]

Superhydrophobic and superoleophilic chitosan sponge (MCTCS) was successfully prepared via a facile freeze-drying method with the assistance of TPP/citral crosslinking and octadecanethiol modification. The three dimensional porous structure endowed the MCTCS sponges with large pore volume and good compressive property. Moreover, the MCTCS sponge could effectively absorb oil with an absorptive capacity up to 60 times of its own weight. More importantly, the MCTCS sponge could selectively absorb the emulsified oils in water effectively, and achieve continuous oil–water separation with the assistance of peristaltic pump. The oil and water separation efficiency was up to 99%. Furthermore, the MCTCS sponge still maintained a highly absorptive capacity after being reused for many cycles and possessed ideal biodegradability. It was believed that the superhydrophobic/superoleophilic chitosan sponge would be a promising absorbent material for the removal of oil from water in environmental remediation. [ABSTRACT FROM AUTHOR]

Background In this study, we aimed to determine if there is a difference in the rates of wound dehiscence, delayed union, nonunion, and unanticipated surgery after the use of bioabsorbable local antibiotic-delivery systems (LADS), specifically comparing antibiotic-impregnated calcium sulfate pellets (Osteoset-T, Wright Medical Technology Inc., Arlington, TN, USA, hereafter referred to as beads) and chitosan sponge (Sentrex BioSponge, Bionova Medical, Germantown, TN, USA, hereafter referred to as sponges) in the management of acute and chronic extremity wounds. Methodology We conducted a retrospective comparative cohort study in the setting of a level 1 trauma center. All patients who received either beads or sponges as an adjunct to surgical debridement from January 2010 to December 2017 were included, and 136 patients met the inclusion criteria. The intervention studied was extremity wounds that were treated with bioabsorbable LADS, either beads or sponges. The main outcome measurement was wound dehiscence and the need for unanticipated surgery. Results Of the 136 patients in the study cohort, 78% (106/136) were treated with beads, and 22% (30/136) were treated with sponges. Of the 136 patients, 50 (37%) experienced wound dehiscence, and 49 patients required unanticipated surgery. Overall, 62% (31/50) of patients with wound dehiscence and 67.4% (33/49) of patients requiring unanticipated surgery were seen in the bead cohort (p = 0.0001 and 0.025, respectively). However, in multivariable analyses, we found that the odds of having wound dehiscence and undergoing unanticipated surgery were, respectively, 4.9 (p = 0.001) and 2.8 (p = 0.021) times more likely to occur in the sponge than in the bead group. Conclusions Sentrex sponges appear to be associated with higher rates of wound dehiscence and the need for unanticipated surgery compared to Osteoset beads., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, McKee et al.)

An injectable, guanosine 5′-diphosphate (GDP)-crosslinked chitosan sponge was investigated as a drug delivery system (DDS) for accelerating biomineralization in critical size bone defects (CSBDs). Two approaches were examined both individually, and in combination, in order to achieve this goal. The first approach involved the encapsulation and release of Bone Morphogenetic Protein 7 (BMP-7), a powerful mineralization stimulant. Results confirmed that the rapid gelation of the chitosan sponge prompted high encapsulation of BMP-7 and provided a controlled release over a period of 30 days with no burst release. The second approach was aimed at encapsulating pyrophosphatase (PPtase) in the chitosan sponge to cleave pyrophosphate (PPi) – a mineralization inhibitor and a degradation by-product of the chitosan sponge – into phosphate ions (Pi). PPtase was successfully encapsulated in the chitosan sponge and was able to completely eliminate PPi from the media by cleaving them to Pi. Chitosan sponges releasing Pi into the media were shown to increase overall biomineralization fourfold as compared to controls, an amount equivalent to biomineralization caused by direct injection of 1 μg of free BMP-7 to the cells. Even though the combined encapsulation of 1 μg BMP-7 and PPtase in the sponges did not demonstrate an additional increase in biomineralization, encapsulation of low concentrations of BMP-7 can promote mesenchymal stem cell migration into the sponge after application in vivo. The findings suggest that the sponge-PPtase system likely allows excellent bone regeneration with lower concentrations of BMP-7, reducing risks and expense of the treatment. Statement of significance There are bone defects, known as critical size defects, which do not heal on their own and require a therapeutic intervention. The current commercially-available therapies use large quantities of growth factors, such as Bone Morphogenetic Proteins (BMPs), which makes them expensive and a source for a myriad of unwanted side effects. In this manuscript we demonstrate, for the first time, the use of an injectable chitosan-based sponge that contains no inorganic components, but can nonetheless act as a source of phosphate ions to improve bone mineralization. We also demonstrate that this sponge can entrap small concentrations of BMP-7 and provide controlled release over time. The ability to release phosphate ions and low concentrations of BMP-7 makes this therapeutic intervention clinically-relevant, affordable, and safe. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to develop and characterize the chitosan sponges loading with doxycycline hyclate and their antibacterial activities. The pore density of chitosan sponge prepared with freeze drying technique was increased as the higher concentrated chitosan solution was used. The sponge prepared from 10% w/ w of the chitosan solution and crosslinking with glutaraldehyde solution was utilized for loading with doxycycline hyclate. The drug release and sustainable antibacterial activity of fabricated sponge were assessed using dissolution test and agar diffusion test, respectively. Drug release from non-crosslinked sponge into phosphate buffer pH7.4 was slower than that from crosslinked sponge since the former could absorb the medium and form gel to retard the initial drug diffusion. Sustainable antibacterial activity of developed sponge was evident against S. aureus and E. coli. In conclusion, the in vitro release profile and antibacterial efficiency indicated that doxycycline hyclate could be sustained using chitosan sponge. [ABSTRACT FROM AUTHOR]

Periodontal disease is the main reason for tooth loss in adults. Tissue engineering and regenerative medicine are advanced technologies used to manage soft and hard tissue defects caused by periodontal disease. We developed a transforming growth factor-β3/chitosan sponge (TGF-β3/CS) to repair periodontal soft and hard tissue defects. We investigated the proliferation and osteogenic differentiation behaviors of primary human periodontal ligament stem cells (hPDLSCs) to determine the bioactivity and potential application of TGF-β3 in periodontal disease. We employed calcein-AM/propidium iodide (PI) double labeling or cell membranes (CM)-Dil labeling coupled with fluorescence microscopy to trace the survival and function of cells after implantation in vitro and in vivo. The mineralization of osteogenically differentiated hPDLSCs was confirmed by measuring alkaline phosphatase (ALP) activity and calcium content. The levels of COL I, ALP, TGF-βRI, TGF-βRII, and Pp38/t-p38 were assessed by western blotting to explore the mechanism of bone repair prompted by TGF-β3. When hPDLSCs were implanted with various concentrations of TGF-β3/CS (62.5–500 ng/mL), ALP activity was the highest in the TGF-β3 (250 ng/mL) group after 7 d (p < 0.05 vs. control). The calcium content in each group was increased significantly after 21 and 28 d (p < 0.001 vs. control). The optimal result was achieved by the TGF-β3 (500 ng/mL) group. These results showed that TGF-β3/CS promotes osteogenic differentiation of hPDLSCs, which may involve the p38 mitogen-activated protein kinase (MAPK) signaling pathway. TGF-β3/CS has the potential for application in the repair of incomplete alveolar bone defects. [ABSTRACT FROM AUTHOR]