Effect of chitosan on lingual hemostasis in rabbits

A phellinus igniarius polysaccharide/chitosan-arginine hydrogel for promoting diabetic wound healing

Inadequate angiogenesis and inflammation at the wound site have always been a major threat to skin wounds, especially for diabetic wounds that are difficult to heal. Therefore, hydrogel dressings with angiogenesis and antibacterial properties are very necessary in practical applications. This study reported a hydrogel (PCA) based on L-arginine conjugated chitosan (CA) and aldehyde functionalized polysaccharides of Phellinus igniarius (OPPI) as an antibacterial and pro-angiogenesis dressing for wound repair in diabetes for the first time. and discussed its possible mechanism for promoting wound healing. The results showed that PCA had good antioxidant, antibacterial, biological safety and other characteristics, and effectively promoted the healing course of diabetic wound model. In detail, the H&E and Masson staining results showed that PCA promoted normal epithelial formation and collagen deposition. The Western blot results confirmed that PCA decreased the inflammation by inhibiting the IKBα/NF-κB signaling pathway and enhanced angiogenesis by adjusting the level of HIF-1α. In conclusion, PCA is a promising candidate for promoting wound healing in diabetes. Graphic abstract.

The potential of chitosan-based haemostats for use in neurosurgical setting - Literature review

Haemorrhage is a major nuance in neurosurgery since blood can distort the surgeon's field of view and increase the risk of post-operative complications. Currently a variety of commercially available haemostats have been approved for use in neurosurgery, but they have caveats to their use in the brain, including, localised tissue compression, neural toxicity, induce immune reaction or form thrombus within the vessel. Thus, there is a need for haemostats that are efficacious and safe for application on brain and spinal tissue. Chitosan is a naturally occurring bio-polymer that is found on the exoskeleton of arthropods and the cell wall of fungi. Chitosan has been shown to accelerate haemostasis through a myriad of physiological pathways. These findings have led to the development of multiple chitosan-based haemostats, for use in peripheral human tissue. Although, clinical data regarding the use of chitosan-based haemostats in the brain is lacking, a range on in vivo studies have proven chitosan to be efficacious and safe in managing neurosurgical bleeds. Similarly, literature comparing chitosan-based haemostats with commercial haemostats used commonly in neurosurgery, have all demonstrated chitosan to be the superior agent. Additionally, clinical trials of chitosan-based haemostat used in peripheral tissue have all demonstrated chitosan to be safe for human use. The marriage of these findings indicates that the safety and superior efficacy of chitosan-based haemostat, makes it a potentially suitable haemostat for use in neurosurgical setting. However, further research pertaining to the clinical use of chitosan-based haemostat within the central nervous system needs to be conducted.

Chitosan-based multifunctional flexible hemostatic bio-hydrogel

Realizing the potential application of chitosan as an effective biomedical hemostatic agent has become an emerging research hotspot. However, fabricating a flexible chitosan-based hemostatic bio-hydrogel with self-adhesion feature in humid conditions and rapid hemostasis capability remains a challenge. Herein, we reported the development of chitosan-based hydrogels (DCS-PEGSH gels) with typical multilevel pore structures, which were cross-linked by 3-(3,4-dihydroxyphenyl) propionic acid-modified chitosan (DCS) and sebacic acid-terminated polyethylene glycol modified by p-hydroxybenzaldehyde (PEGSH). By precisely regulating the proportion of PEGSH, the fabricated bio-hydrogels displayed favorable cytocompatibility, suitable stretchability (∼780%), and blood absorbability (1300% ± 50%). Moreover, the strong adhesion (∼68.5 kPa) of the assembled bio-hydrogel ensured its firm adherence on pigskin and on bleeding wound in both static and dynamic humid environments without shedding, thus providing a long service life. The fabricated hydrogels exhibited shorter blood clotting time (50 s) and lower blood clotting index (BCI, 41) than the commercial chitosan sponge (288 s, BCI 65). Notably, the amount of blood loss from the liver in mice was reduced by almost 90% as compared to that for the control group. This study paves a solid way for developing a chitosan-based hydrogel with self-adhesive, self-healing, stretchability, biocompatibility, and antibacterial and antioxidant properties through molecular design and structural regulation, which will enable the biomedical application of chitosan in emergency hemostasis, particularly in joints and extremities. STATEMENT OF SIGNIFICANCE: The design and preparation of multifunctional integrated green adhesive bio-hydrogels while avoiding the use of organic solvents and toxic chemical reagents has been an emerging challenge. Herein, a flexible chitosan-based hemostatic bio-hydrogel that integrates multifunctional properties was successfully synthesized. The bio-hydrogel displayed suitable stretchability (780%) and blood absorbability (1300% ± 50%). Moreover, the strong adhesion (68.5 kPa) ensured firm adherence of the assembled hydrogel on pigskin and on the bleeding wound site in both static and dynamic humid environments without shedding, thus providing a long service life. In addition, the designed hydrogel showed good compatibility and antibacterial performance. The dynamic Schiff base endowed the bio-hydrogel with excellent self-healing performance without any external stimuli.

Effects of degree of deacetylation on hemostatic performance of partially deacetylated chitin sponges

Chitin/chitosan hemostatic materials have long been studied for uncontrolled hemorrhage, an urgent clinical problem due to severe blood-vessel damage or hemophilia. As one of the basic structural parameters of chitin, the degree of deacetylation (DD) significantly affects the material's physical, chemical, as well as biological properties. In this study, partially deacetylated chitins with a wide range of DD (23-81%) were prepared by homogeneous deacetylation, and sponges with these various chitins were fabricated by freeze-drying to study the effects of DD on their hemostatic properties. Among all sponge samples, the chitosan sponge with a DD of 48% showed the highest water absorption, whole blood adsorption, RBC adsorption rate, and the best hemostatic performance in an uncontrolled bleeding model of the rat femoral artery, demonstrating that a certain proportion of acetyl amino and amino groups could also activate the coagulation system and promote the adhesion of platelet and erythrocyte.

Crab vs. Mushroom: A Review of Crustacean and Fungal Chitin in Wound Treatment

Chitin and its derivative chitosan are popular constituents in wound-treatment technologies due to their nanoscale fibrous morphology and attractive biomedical properties that accelerate healing and reduce scarring. These abundant natural polymers found in arthropod exoskeletons and fungal cell walls affect almost every phase of the healing process, acting as hemostatic and antibacterial agents that also support cell proliferation and attachment. However, key differences exist in the structure, properties, processing, and associated polymers of fungal and arthropod chitin, affecting their respective application to wound treatment. High purity crustacean-derived chitin and chitosan have been widely investigated for wound-treatment applications, with research incorporating chemically modified chitosan derivatives and advanced nanocomposite dressings utilizing biocompatible additives, such as natural polysaccharides, mineral clays, and metal nanoparticles used to achieve excellent mechanical and biomedical properties. Conversely, fungi-derived chitin is covalently decorated with -glucan and has received less research interest despite its mass production potential, simple extraction process, variations in chitin and associated polymer content, and the established healing properties of fungal exopolysaccharides. This review investigates the proven biomedical properties of both fungal- and crustacean-derived chitin and chitosan, their healing mechanisms, and their potential to advance modern wound-treatment methods through further research and practical application.

Thermogelling chitosan-based polymers for the treatment of oral mucosa ulcers

Current treatments for oral mucosa-related ulcers use drugs to relieve pain and promote healing, but rarely consider drug resistance to bacterial infection in the microenvironment of the oral cavity or the prevention of bleeding from gingival mucosa ulcers. We herein report an injectable, thermogelling chitosan-based system to address these concerns. An aqueous solution of chitosan-based conjugates (chitosan-g-poly(N-isopropylacrylamide) [CS-g-PNIPAAM] including 1a [CS-g-PNIPAAM with less PNIPAAM] and 1b [CS-g-PNIPAAM with more PNIPAAM], and chitosan-g-poly(N-isopropylacrylamide)-g-polyacrylamide [CS-g-PNIPAAM-g-PAM] 3) could reversibly form semi-solid gels at physiological temperatures for easy application to oral cavity ulcer sites by injection. The chitosan-based conjugate thermogels prepared could inhibit both Gram-positive and Gram-negative bacteria and the two with higher chitosan and poly(N-isopropylacrylamide) contents (1a and 1b) promoted proliferation of gingival fibroblasts in vitro. These two thermogels also exhibited improved blood clotting in an in vivo rat study. Thermogels 1a and 1b effectively promoted ulcer healing and shortened ulcer healing times in an oral gingival mucosa ulcer model using Sprague Dawley (SD) rats. These thermogels showed no obvious toxicity to the main organs of SD rats undergoing gingival ulcer treatment. These results suggest that this antibacterial biomaterial could be a promising injectable therapeutic agent for the treatment for oral mucosa ulcers.

Safety and Efficacy of Topical Chitogel- Deferiprone-Gallium Protoporphyrin in Sheep Model

Objectives: Increasing antimicrobial resistance has presented new challenges to the treatment of recalcitrant chronic rhinosinusitis fuelling a continuous search for novel antibiofilm agents. This study aimed to assess the safety and efficacy of Chitogel (Chitogel®, Wellington New Zealand) combined with novel antibiofilm agents Deferiprone and Gallium Protoporphyrin (CG-DG) as a topical treatment against S. aureus biofilms in vivo.

Methods: To assess safety, 8 sheep were divided into two groups of 7 day treatments (n = 8 sinuses per treatment); (1) Chitogel (CG) with twice daily saline flush, and (2) CG-DG gel with twice daily saline flush. Tissue morphology was analyzed using histology and scanning electron microscopy (SEM). To assess efficacy we used a S. aureus sheep sinusitis model. Fifteen sheep were divided into three groups of 7 day treatments (n = 10 sinuses per treatment); (1) twice daily saline flush (NT), (2) Chitogel (CG) with twice daily saline flush, and (3) CG-DG gel with twice daily saline flush. Biofilm biomass across all groups was compared using LIVE/DEAD BacLight stain and confocal scanning laser microscopy.

Results: Safety study showed no cilia denudation on scanning electron microscopy and no change in sinus mucosa histopathology when comparing CG-DG to CG treated sheep. COMSTAT2 assessment of biofilm biomass showed a significant reduction in CG-DG treated sheep compared to NT controls.

Conclusion: Results indicate that CG-DG is safe and effective against S. aureus biofilms in a sheep sinusitis model and could represent a viable treatment option in the clinical setting.

Characterization of PCL and Chitosan Nanoparticles as Carriers of Enoxaparin and Its Antithrombotic Effect in Animal Models of Venous Thrombosis

This study was based on the preparation, characterization, and animal in vivo experiments performed to evaluate nanoparticles of poly(ɛ-caprolactone) (PCL) and chitosan as carriers of enoxaparin. The nanoparticles were characterized and presented satisfactory results in terms of size, polydispersity, and encapsulation efficiency. Anticoagulant activity of the nanoparticles was maintained for 14 hours when the administration was subcutaneous; however no activity was observed after oral administration. There was a significant reduction in thrombus size, in vivo, for both free and encapsulated enoxaparin in comparison with the control group after subcutaneous administration. Oral administration results however were indifferent. In conclusion, the double emulsion method w/o/w was efficient for enoxaparin encapsulation, producing spherical nanoparticles with high encapsulation efficiency. For in vivo studies, the encapsulated enoxaparin showed a sustained anticoagulant activity for a higher period of time compared to free enoxaparin, with an antithrombotic effect when administered subcutaneously.

Hemostyptic property of chitosan: Opportunities and pitfalls

BACKGROUND

Chitosan is used in a wide field of applications and therapies and has been reported to be an effective hemostyptic. The objective of this study was to provide further information about the use of chitosan as a hemostyptic agent also taking into focus its hemocompatible effects.

METHODS

Human whole blood (n=5) was anticoagulated with heparin, treated with different chitosan concentrations (0, 2.5, 5, 7.5, 10, 12.5, 25 mg/mL) and incubated at 37°C for 30 minutes. Before and after incubation different parameters for coagulation and hemocompatibility were evaluated.

RESULTS

Blood treated with high chitosan concentrations showed enhanced coagulation, which we evaluated with activated clotting time, activated partial thromboplastin time and concentration of thrombin-antithrombin complexes. Furthermore, we observed an activation of blood platelets, complement cascade and granulocytes in the groups treated with chitosan.

CONCLUSION

Our data indicate that chitosan activates human blood coagulation and hence has good properties as a hemostyptic agent. However, inflammatory parameters were upregulated after direct contact with human blood indicating that systemic administration of chitosans should not be performed whereas the topical use of chitosan as a hemostypticum should not present any hazard with regard to adverse inflammatory reactions at the site of application.

Recent advances in topical agents for prehospital haemostasis

The prehospital treatment of severe extremity bleeding has remained unchanged for years and relies on compression with absorbent gauze dressings. Advances in haemostasis technology have identified several new methods of improving bleeding control. These are examined with a view to possible inclusion in a new prehospital dressing aimed at reducing the degree of exsanguination and associated mortality and morbidity from a major extremity injury.

Effect of a Chitosan Gel on Hemostasis and Prevention of Adhesion After Endoscopic Sinus Surgery

OBJECTIVES

Postoperative bleeding and adhesion formation are the two most common complications after endoscopic sinus surgery (ESS). The former sometimes can be life threatening and the latter is the most common reason requiring revision surgery. This study was designed to evaluate the effect of newly developed chitosan gel (8% carboxymethyl chitosan, Surgi shield) on hemostasis and wound healing after ESS.

METHODS

A prospective, randomized, double-blind controlled trial was conducted in 33 patients undergoing symmetric ESS. At the conclusion of the operation, Surgi shield was randomly applied on one side of the nasal cavity, with the opposite side acting as control and the bleeding quantity of the surgical field was evaluated every 2 minutes. And then, Merocel was placed in the ethmoidectomized areas of the both sides. Five milliliters of Surgi shield was applied to the Merocel of intervention side and saline was applied to the other side. Merocel in both nasal cavities was removed and 5 mL of Surgi shield was applied again to the intervention side on the second day after surgery. The nasal cavity was examined using a nasal endoscope and the degree of adhesion, crusting, mucosal edema, infection, and granulations were graded at 1, 2, and 4 weeks after surgery.

RESULTS

Complete hemostasis was rapidly achieved in the Surgi shield applied side compared with the control side at 2, 4, 6, 8, and 10 minutes after application of Surgi shield (P=0.007, P=0.004, P<0.001, P=0.001, and P<0.001, respectively). There were significantly less adhesions on the Surgi shield applied side at postoperative 1, 2, and 4 weeks (P=0.001, P<0.001, and P<0.001, respectively). The degree of mucosal edema, infection, crusting, or granulation formation assessed by the endoscopic features in the Surgi shield applied side was not significantly different from that of the control side (P>0.05). No adverse effects were noted in the patient series.

CONCLUSION

Surgi shield containing chitosan can be used safely to achieve rapid hemostasis immediately after ESS and to prevent adhesion formation.

Effect of Plasma Sterilization on the Hemostatic Efficacy of a Chitosan Hemostatic Agent in a Rat Model

INTRODUCTION

The United States military has had success with chitosan (CS)-based hemostatic agents to control trauma-induced hemorrhages. Despite the positive reviews, additional physical forms of CS may enhance its hemostatic efficacy. Additionally, standard sterilization techniques may negatively affect the hemostatic efficacy of CS. We studied the effects of a CS-based hemostatic pad, the Clo-Sur P.A.D.™ (Scion Cardio-Vascular, Inc.), on severe femoral vessel bleeding in a rat model. The effects of different sterilization techniques on the bioadhesivity, surface atomic concentrations, and hemostatic efficacy of the P.A.D. were also evaluated.

METHODS

Hemostatic efficacy, bioadhesivity, and surface atomic concentrations of the P.A.D. were evaluated in its unsterilized form, after sterilization with standard e-beam treatment, and after sterilization with one of three types of non-thermal nitrogen plasma: nitrogen gas, air, or nitrous oxide plasma. After standardized puncture of the femoral artery or transection of the femoral vessels, rats were treated with either a CS P.A.D. or gauze pad.

RESULTS

The Clo-Sur P.A.D., regardless of sterilization technique, stopped arterial and mixed arterial/venous bleeding in all cases in <90 s with the time to hemostasis (TTH) significantly less for all P.A.D. treatment groups (P < 0.001; n = 4-5/group) compared to gauze-treated controls (n = 3). E-beam sterilized P.A.D.s consistently showed non-significant trends toward increased TTH and worse hemostasis scores compared to unsterilized and plasma sterilized P.A.D.s. Treating e-beam sterilized P.A.D.s with N2 plasma reverted the hemostatic efficacy to levels equivalent to native, unsterilized PADs.

CONCLUSION

A CS-based hemostatic pad successfully controlled severe bleeding in a rat model with combined e-beam and plasma sterilized P.A.D.s showing the most promising results. Further studies are warranted.

Biodegradable nasal packings for endoscopic sinonasal surgery: a systematic review and meta-analysis

OBJECTIVES

To assess biodegradable nasal packing effectiveness for improving postoperative symptoms and mucosal healing after endoscopic sinonasal surgery as compared with conventional/non-packing groups.

METHODS

Relevant articles were searched on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. We included randomized controlled trials (RCTs) that compared biodegradable packings with conventional packings or no packing, reporting postoperative symptoms and/or mucosal healing outcomes.

RESULTS

This review included 19 studies, of which 11 compared biodegradable packings with conventional packings. Meta-analysis found that biodegradable packings significantly improved postoperative symptoms: bleeding at removal, pain at removal, pain in situ, and nasal blockage. Mucosal healing outcomes were inconsistent within studies, with no data could be pooled. Eight studies compared biodegradable packings with non-packing group. Postoperative symptom data in this comparison could not be pooled: A protective or equal effect on postoperative bleeding was reported in different studies; no difference was reported in pain status and nasal blockage. As for mucosal healing, meta-analysis showed that two arms of comparison had similar effect on synechiae, edema, infection and granulation at each time point.

CONCLUSION

The limiting evidence suggests that biodegradable nasal packings are statistically better than conventional packings in postoperative symptoms, and probably comparable to non-packing group, as in this comparison we could not carry out meta-analysis. No beneficial or detrimental effect on postoperative mucosal healing could be determined based on existing evidence.

Effect of recombinant human epidermal growth factor impregnated chitosan film on hemostasis and healing of blood vessels

Background

Bleeding can be a problem in wound debridement. In search for an effective hemostatic agent, we experimented with a chitosan film combined with the recombinant human epidermal growth factor (rh-EGF), hypothesizing that it would achieve effective hemostasis and simultaneously enhance arterial healing.

Methods

Forty-eight Sprague-Dawley rats were used, and 96 puncture wounds were made. The wounds were divided into the following four groups: treated with sterile gauze, treated with gelatin sponge, treated with chitosan, and treated with chitosan combined with rh-EGF. Immediate hemostasis was evaluated, and arterial healing was observed histologically.

Results

Groups B, C, and D showed a significant rate of immediate hemostasis as compared to group A (P<0.05), but there were no significant differences among groups B, C, and D. Histologically, only group D showed good continuity of the vessel wall after 1 week. It was the only group to show smooth muscle cell nuclei of the vessel wall.

Conclusions

We observed that chitosan has an effective hemostatic potential and the mix of rh-EGF and chitosan does not interfere with chitosan's hemostatic capabilities. We also identified enhanced healing of vessel walls when rh-EGF was added to chitosan. Further research based on these positive findings is needed to evaluate the potential use of this combination on difficult wounds like chronic diabetic ulcerations.

Investigation of acetylated chitosan microspheres as potential chemoembolic agents

The aim was to investigate the potential of chitosan microspheres (CMs) with different acetylation using as a chemoembolic agent. Chitosan microspheres (CMs) were prepared via water-in-oil (W/O) emulsification cross-linking method, and acetylated chitosan microspheres (ACMs) were obtained by acetylation of CMs. Next, we characterized the morphology, size, composition and degrees of deacetylation using scanning electron microscopy (TEM), dynamic laser light scattering (DLS), and Fourier transform infrared spectrometer (FTIR). All microspheres had smooth surfaces and good mechanical flexibility, and all could pass through a 5F catheter. The swelling rate (SR) of CMs decreased significantly with the increase of pH (4.0-10.0) but ACMs did not change under the same conditions. Protein absorption assays suggested that albumin was more greatly adsorbed on CMs than on ACMs. Furthermore, CMs caused more blood clots than ACMs. ACMs caused hemolysis less than CMs (<5% of the time). Data indicated that ACMs had more hemocompatibility. Cytotoxicity tests indicated that ACMs initially had less cell attached proliferation but increased with incubation. In contrast, the relative growth rate of mouse embryo fibroblasts (MEFs) on CMs decreased gradually. The results suggested that ACMs could stimulate the growth of MEFs, and CMs were not cytotoxic to MEFs. Thus, ACMs were more biocompatible with greater potential to be used as chemoembolic material.

Should chitosan and tranexamic acid be combined for improved hemostasis after sinus surgery?

Chitosan, a β-1,4-linked polymer of glucosamine with lesser amounts of N-acetylglucosamine, has well-recognized hemostatic properties. Chitosan is also able to open tight cellular junctions, facilitating paracellular drug transport and delivery. Chitosan, through topical application, facilitates the systemic delivery of analgesic drugs. Theoretically this ability could be used to enhance the local delivery of hemostatic drugs, such as tranexamic acid, improving chitosan's role as a topical dressing. Individually a chitosan-dextran gel and tranexamic acid have been shown to improve hemostasis after endoscopic sinus surgery. A combination of both should lead to improved hemostasis and better postsurgical outcomes. The use of a chitosan/tranexamic acid dressing could have a wide range of potential beneficial applications in a number of other clinical surgical settings. While the initial main application might be as an improved external hemostatic dressing, it should also be useful on a range of internal surgical wounds.

Blood contact properties of ascorbyl chitosan

Ascorbyl chitosan was synthesized by heating chitosan with ascorbic acid in isopropanol. The products were characterized by FTIR and C-13 NMR spectroscopies, SEM, and elemental analysis. Blood contact properties of ascorbyl chitosans were evaluated. The ascorbyl chitosans demonstrated to have increased lipid-lowering activity in comparison to chitosan alone upon contact with human blood serum in in vitro conditions. Furthermore, the total cholesterol/HDL ratio was improved towards the desirable ideal values after three hours contact with ascorbyl chitosan samples. The lipid-lowering activity increased with ascorbyl substitution. The inherent nonspecific adsorption capability of chitosan due to its chelating power with several different functional groups was exhibited by ascorbyl chitosans as well. This behavior was exemplified in a simultaneous decrease in the total iron values of the volunteers together with lower lipid levels. Furthermore, ascorbyl chitosans were observed to have less hemocompatibility but increased anticoagulant activity when compared to chitosan alone. Additional in vivo studies are necessary to support these results and to investigate further the advantages and disadvantages of these materials to prove their safety prior to clinical applications.

Hematotoxicological analysis of surface-modified and -unmodified chitosan nanoparticles

The increasing interest in using chitosan nanoparticles for controlled drug delivery is hampered by its blood incompatibility, especially for intravenous applications. This study investigated the effects of processing solvents (acetic acid/lactic acid), dispersing media (acidic medium/saline), and surface modifiers (polyethylene glycol, polyvinyl alcohol, and ethylenediaminetetraacetatic acid) on the hemocompatibility of chitosan. Blood compatibility of chitosan nanoparticles prepared by ionotropic gelation with altered surface chemistry was evaluated by assessing their hemolytic activity, platelet aggregation, coagulation, and cytokine induction. It was observed that nanoparticles prepared in lactic acid and dispersed in saline did not show hemolysis, platelet aggregation, or coagulation, whereas nanoparticles prepared in acetic acid showed strong hemolysis. Surface modifiers were not observed to significantly affect blood compatibility, with the exception of EDTA, which delayed blood clotting times. Thus, chitosan nanoparticles prepared in lactic acid and dispersed in saline may be an ideal nanocarrier for parenteral applications.

Positive charge of chitosan retards blood coagulation on chitosan films

In this study, a series of chitosan films with different protonation degrees were prepared by deacidification with NaOH aqueous or ethanol solutions. The films were then used as a model to investigate the effects of the positive charge of chitosan on blood coagulation. The results showed that the positive charge of chitosan acted as a double-edged sword, in that it promoted erythrocyte adhesion, fibrinogen adsorption, and platelet adhesion and activation, but inhibited activation of the contact system. In contrast to prevailing views, we found that the positive charge of chitosan retarded thrombin generation and blood coagulation on these films. At least two reasons were responsible for this phenomenon. First, the positive charge inhibited the contact activation, and second, the positive charge could not significantly promote the activation of non-adherent platelets in the bulk phase during the early stage of coagulation. The present findings improve our understanding of the events leading to blood coagulation on chitosan films, which will be useful for the future development of novel chitosan-based hemostatic devices.

The efficacy of a novel chitosan gel on hemostasis and wound healing after endoscopic sinus surgery

BACKGROUND

Postoperative bleeding and adhesion formation are the two most common complications after endoscopic sinus surgery (ESS). Continued bleeding risks airway compromise from the inhalation of blood clots and from the aspiration of blood-stained vomitus. Additionally, adhesion formation is the most common reason for patients requiring revision surgery. This study aimed to determine the efficacy of a novel chitosan/dextran (CD) gel on hemostasis and wound healing after ESS.

METHODS

A randomized controlled trial was performed involving 40 patients undergoing ESS for chronic rhinosinusitis. Immediately after surgery a baseline Boezaart Surgical Field Grading Scale was taken. Computer randomization was performed with one side receiving CD gel and the other side receiving no treatment (control). Boezaart bleeding scores were then calculated for each side every 2 minutes. Patient's endoscopic features of wound healing were assessed at 2, 6, and 12 weeks after surgery.

RESULTS

CD gel achieved rapid hemostasis with the mean time to hemostasis at 2 minutes (95% CI, 2-4 minutes) compared with 10 minutes (95% CI, > or =6 minutes) for the control (p < 0.001). There were significantly less adhesions at all time points with CD gel versus control: 2 versus 18 at 2 weeks (p < 0.001), 3 versus 16 at 6 weeks (p < 0.001), and 2 versus 12 at 3 months (p < 0.001). There was no significant difference between CD gel and control with respect to crusting, mucosal edema, infection, or granulation tissue formation.

CONCLUSION

CD gel is rapidly hemostatic immediately after ESS and prevents adhesion formation, addressing two of the most common complications of sinus surgery.

Nasal dressings after endoscopic sinus surgery: what and why?

PURPOSE OF REVIEW

Nasal dressings are commonly used following endoscopic sinus surgery in an attempt to prevent ongoing bleeding and to modulate the wound healing process. Experience with nasal dressings in the otolaryngologic literature spans more than half a century; however, despite this, there is still little agreement between surgeons on the optimal choice of nasal dressings following endoscopic sinus surgery, or whether nasal dressings are required at all. This paper briefly reviews the past research and examines recent advances in the area of nasal dressings.

RECENT FINDINGS

The ideal nasal dressing is one that is absorbable, hemostatic and improves healing. Although a number of currently available materials may address one of these features, none address all. Currently available dressings that achieve hemostasis worsen wound healing outcomes. However, recent research shows promise with microporous polysaccharide hemospheres and chitosan gel having promising effects on hemostasis, and chitosan gel showing a significant adhesion prevention effect.

SUMMARY

The sinus surgeon must be aware of the potential advantages and limitations of currently available nasal dressings. The area of wound healing and adhesion prevention remains an area of active research and more prospective controlled trials are needed to define any benefits biomaterials may have.

Fabrication and characterization of chitosan coated braided PLLA wire using aligned electrospun fibers

The development of functionalized braided wires coated with chitosan that can be used for tissue suturing and tissue regeneration is the subject of this work. Poly(L: -lactic acid) (PLLA) braided wires were successfully fabricated by combining an electrospinning technique and alignment collection with a mini-type braiding method. The resulting PLLA wires with and without chitosan coating were characterized through a variety of methods including scanning electron microscopy (SEM), X-ray photoelectronic spectra (XPS) and tensile mechanical testing. Hemolytic property, kinetic hemostasis behavior, platelet adhesion, erythrocyte adhesion, and water uptake ability of the wires were explored. The results showed that a nearly comparable mechanical behavior of the braided wires with some commercial suture could be obtained with well-aligned fibers, and no significant difference in tensile performances were recognized with and without the introduction of chitosan. The PLLA wires coated with chitosan were found to have better prohemostatic activity than those without a chitosan coating.

The safety of chitosan as a pharmaceutical excipient

Interest in use of the polysaccharide chitosan as a pharmaceutical excipient by different dose routes and for a number of applications is not new but it still does not appear to be present in any marketed drugs. Including a novel excipient in a new drug formulation requires a number of safety considerations. Review of the published literature showed that chitosan has low oral toxicity and local tolerance potential supporting use in non-parenteral formulations. Prior human oral exposure has occurred through use of chitosan dietary supplements and food additive, medical device and cosmetic applications. Although systemic exposure to parent chitosan may be limited (due to digestion in the gastrointestinal tract), any that is absorbed will likely undergo enzyme degradation to naturally occurring glucosamine, and N-acetylglucosamine, its copolymers, which are excreted or used in the amino sugar pool. Chitosan has local biological activity in the form of haemostatic action and, together with its ability to activate macrophages and cause cytokine stimulation (which has resulted in interest in medical device and wound healing applications), may result in a more careful assessment of its safety as a parenteral excipient.

The Efficacy of a Novel Chitosan Gel on Hemostasis after Endoscopic Sinus Surgery in a Sheep Model of Chronic Rhinosinusitis

Background

Postoperative bleeding remains a major problem after endoscopic sinus surgery (ESS). Patients who continue to bleed after ESS are at risk of airway compromise from inhalation of blood clots or from aspiration of blood-stained vomitus. The aim of this study was to determine the in vivo efficacy of a novel gel on hemostasis after ESS in a sheep model of chronic rhinosinusitis.

Methods

Twenty-one sheep infested with Oestrus ovus underwent ESS with standardized mucosal injuries created at the anterior ethmoid region using a microdebrider. Immediately after injury a baseline bleeding time was taken using the Boezaart Surgical Field Grading Scale. Computer randomization was performed to either receive chitosan/dextran (CD) gel or no treatment (control). Boezaart bleeding scores were calculated for each side every 2 minutes. Each postoperative day videoendoscopy was performed to document crusting/CD gel dissolution.

Results

The CD gel side was significantly more hemostatic at 2, 4, and 6 minutes after injury. Average time to hemostasis was significantly better for the intervention side versus control side, 4.09 (±1.61) versus 6.57 (±2.20), respectively (p = 0.049). Complete hemostasis occurred by 6 minutes for all CD gel sides; however, control side bleeding was noted on three sides at 8 minutes and on one side at 10 minutes. There was no significant difference in crusts scores at days 1, 3, 7, and 14.

Conclusion

In the sheep model of ESS, CD gel significantly improved hemostasis compared with the control at 2, 4, and 6 minutes after mucosal injury.

Osteogenic activity of the mixture of chitosan and particulate dentin

To evaluate the healing effect of a mixture of chitosan and particulate dentin, a 8-mm-diameter critical size defect was created in the calvarium of 75 rats. The rats were divided into four experimental groups and a control group (no treatment). The defects in the experimental groups were grafted either with pig particulate dentin (group 1), a mixture of particulate dentin and plaster of Paris (group 2), particulate dentin and chitosan (group 3), or chitosan only (group 4). Rats in each group were sacrificed 2, 4, and 8 weeks after implantation. All experimental groups showed more new bone formation when compared to the control group. Additionally, all groups exhibited more bone growth at 8 weeks than at 4 weeks after implantation. It was concluded from this study that defects treated with particulate dentin powder-chitosan mixture may mediate an excellent effect on the formation of new bones.

Effects of a novel chitosan gel on mucosal wound healing following endoscopic sinus surgery in a sheep model of chronic rhinosinusitis

INTRODUCTION

Postoperative bleeding and adhesion formation remain the two major problems after endoscopic sinus surgery (ESS). This study investigates the effect on adhesion formation and wound healing in a sheep model of chronic sinusitis of three topical agents: recombinant tissue factor (rTF, Dade Innovin, Marburg, Germany), poly-ethylene glycol (SprayGel, Confluent Surgical, Waltham, MA), and a novel chitosan-dextran derivative gel (CD, Department of Chemistry, University of Otago, Dunedin, New Zealand).

METHODS

Twenty sheep with chronic sinusitis underwent ESS with standardized mucosal injuries created on the lateral nasal wall and the ethmoid region. Injured areas were divided into four groups, and one of the three agents or control (no treatment) was randomly applied. The presence and severity of adhesions were noted and the healing was evaluated by taking brushings for ciliary beat frequency and biopsies of the injured regions at day 28, 56, 84, and 112 post initial surgery. The biopsy specimens were assessed for re-epithelialisation using light microscopy and scanning electron microscopy for reciliation. The cytobrush specimens assessed cilial function by measuring ciliary beat frequency.

RESULTS

CD significantly decreased lateral nasal wall and ethmoidal adhesions compared to tissue factor at all time points (5% vs. 25%, and 0 vs. 50%, respectively). There was a noticeable trend toward decreased adhesions on the lateral nasal wall and ethmoids in the SprayGel group (10% and 14%) and the CD group (10% and 0%) compared to controls (15% and 40%). The CD group had a significantly greater percentage of re-epithelialisation at day 28 and day 84 compared to the rTF group (70% vs. 33%, P < .001; 84.5% vs. 61%, P < 0.05). At day 28, the CD group was significantly more ciliated than control (62% vs. 31%, P < .01) and than rTF (62% vs. 23%, P < .001). This difference between CD and rTF reciliation remained significant at day 56 (67% vs. 40%, P < .05). In addition, the mean cilial grade for CD at day 112 was significantly better than control (1.9 vs. 2.7, P < .05).

CONCLUSION

In the sheep model of chronic sinusitis, CD significantly improves microscopic wound healing and reduces adhesion formation after ESS.

Preparation and blood coagulation evaluation of chitosan microspheres

Cross-linked chitosan microspheres (40-100 microm) with smooth surface were prepared by the methods of emulsification and ethanol coagulant. FTIR results showed that the cross-linking reaction occurred on the amino groups of chitosan molecules. The swelling characteristic of chitosan microspheres was influenced by the environment pH, being generally greater at low rather than higher pH values. The coagulation properties of chitosan microspheres were evaluated by dynamic blood clotting, platelet adhesion and activation, erythrocyte adhesion, hemolysis, and protein absorption assays. Chitosan microspheres can shorten the clotting time and induce the adhesion and activation of platelets. But the shortening of clotting time by chitosan microspheres may be related to not only platelet aggregation, but also erythrocyte aggregation. Take together, chitosan microspheres may be potential use as thrombospheres.

Effect of chitosan molecular weight and deacetylation degree on hemostasis

Comparative studies have been carried out among solid-state chitosan soliquoid, chitosan acetic acid physiological saline solution, and carboxymethyl chitosan physiological saline solution to discover the hemostatic effect of molecular weight (M(w)) and deacetylation degree (DA) of chitosan. It was found that solid-state chitosan and chitosan acetic acid physiological saline solution performed different hemostatic mechanisms. When blood mixed with chitosan acetic acid physiological saline solution, the erythrocytes aggregated and were deformed. The DA, especially a low DA, in the chitosan acetic acid physiological saline solution, had a significant effect on the unusual aggregation and deformation of erythrocytes, compared with the effect of M(w) within a range between 10(5) and 10(6). However, this phenomenon could not be observed in solid-state chitosan soliquoid. Solid-state chitosan with a low DA absorbed more platelets and was more hemostatic. Carboxymethyl chitosan physiological saline solution had nothing to do with the aggregation and deformation of erythrocytes but caused local rouleau. The values of thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration (FIB) were measured after the blood was mixed with solid-state chitosan soliquoid, chitosan acetic acid physiological saline solution, and carboxymethyl chitosan physiological saline solution, separately. The results demonstrated that coagulation factors might not be activated by them.

Chitosan-glycerol phosphate/blood implants increase cell recruitment, transient vascularization and subchondral bone remodeling in drilled cartilage defects

OBJECTIVE

Marrow-stimulation techniques are used by surgeons to repair cartilage lesions although consistent regeneration of hyaline cartilage is rare. We have shown previously that autologous blood can be mixed with a polymer solution containing chitosan in a glycerol phosphate (GP) buffer (chitosan-GP), and that implantation of this polymer/blood composite onto marrow-stimulated chondral defects in rabbit and sheep leads to the synthesis of more chondral repair tissue with greater hyaline character compared to marrow-stimulation alone. In the current study, we examined the modulation of cell recruitment and repair tissue characteristics at early post-surgical time points (from day 1 to 56) in a rabbit model to elucidate potential mechanisms behind this improved repair outcome.

DESIGN

Thirty-three skeletally mature New Zealand White rabbits underwent bilateral arthrotomies, with each trochlea receiving a cartilage defect (3.5 mm x 4.5mm) bearing four microdrill holes (0.9 mm diameter, approximately 4 mm deep) into the subchondral bone. One defect per rabbit was treated with a chitosan-GP/blood implant, while the other defect was left as a microdrilled control. Repair tissues were stained by histochemistry, for collagen types I, II, and X by immunohistochemistry and analyzed using quantitative stereological tools.

RESULTS

Histological analyses demonstrated that control defects followed a typical healing sequence observed previously in marrow-stimulation animal models while chitosan-GP/blood implants led to three significant modifications in the healing sequence at early stages: (1) increased inflammatory and marrow-derived stromal cell recruitment to the microdrill holes, (2) increased vascularization of the provisional repair tissue in the microdrill holes, and (3) increased intramembranous bone formation and subchondral bone remodeling (BR).

CONCLUSIONS

These results suggest that the greater levels of provisional tissue vascularization and BR activity are main factors supporting improved cartilage repair when chitosan-GP/blood implants are applied to marrow-stimulated cartilage lesions.

Application of chitosan gel in the treatment of chronic periodontitis

Local administration of antibiotics in periodontal therapy can be provided with an appropriate delivery system. The purpose of this study was to evaluate the clinical effectiveness of chitosan, both as a carrier in gel form and as an active agent in the treatment of chronic periodontitis (CP). The chitosan gel (1% w/w) incorporated with or without 15% metronidazole was prepared and applied adjunctive to scaling and root planing (SRP) in comparison to SRP alone (control group-C), in CP patients. The clinical parameters such as probing depth (PD), clinical attachment level, the amount of gingival recession, plaque index, gingival index, and gingival bleeding time index were recorded at baseline and at weeks 6, 12, and 24. In all groups, significant improvements were observed in clinical parameters between baseline and week 24 (p < 0.05). The reductions in PD values were 1.21 mm for Ch, 1.48 mm for Ch + M, and 0.94 mm for C groups. No complications related to the chitosan were observed in patients throughout the study period. It is suggested that chitosan itself is effective as well as its combination with metronidazole in CP treatment due to its antimicrobial properties.

A special report on the chitosan-based hemostatic dressing: experience in current combat operations

BACKGROUND

Hemorrhage remains a leading cause of death in both civilian and military trauma patients. The HemCon chitosan-based hemostatic dressing is approved by the US Food and Drug Administration (FDA) for hemorrhage control. Animal data have shown the HemCon dressing to reduce hemorrhage and improve survival. The purpose of this article is to report preliminary results of the hemostatic efficacy of the HemCon dressing used in the prehospital setting on combat casualties.

METHODS

A request for case information on use of HemCon dressings in Operation Iraqi Freedom and Operation Enduring Freedom was sent to deployed Special Forces combat medics, physicians, and physician assistants.

RESULTS

Sixty-eight uses of the HemCon dressing were reported and reviewed by two US Army physicians. Four of the 68 cases were determined duplicative resulting in a total of 64 combat uses. Dressings were utilized externally on the chest, groin, buttock, and abdomen in 25 cases; on extremities in 35 cases; and on neck or facial wounds in 4 cases. In 66% of cases, dressings were utilized following gauze failure and were 100% successful. In 62 (97%) of the cases, the use of the HemCon dressing resulted in cessation of bleeding or improvement in hemostasis. There were two reported dressing failures that occurred with blind application of bandages up into large cavitational injuries. Dressings were reported to be most useful on areas where tourniquets could not be applied to control bleeding. The dressings were reported to be most difficult to use in extremity injuries where they could not be placed easily onto or into the wounds. No complications or adverse events were reported.

CONCLUSION

This report on the field use of the HemCon dressing by medics suggests that it is a useful hemostatic dressing for prehospital combat casualties and supports further study to confirm efficacy.

Comparison of Hemorrhage Control Agents Applied to Lethal Extremity Arterial Hemorrhages in Swine

BACKGROUND

QuikClot powder (QC), chitosan dressing (CD), and fibrin sealant dressing (FSD) are new hemostatic products touted to be more effective in controlling severe extremity bleeding than the current standard gauze dressing. All have been utilized in the global war on terrorism. Our objective was to evaluate the hemostatic efficacy of these three products in a model of severe extremity arterial hemorrhage that could not be stopped by standard gauze treatment.

METHODS

A model of severe extremity arterial hemorrhage was developed in swine that was 100% fatal with standard gauze application and manual compression. The Army Field Bandage (AFB) was the standard gauze control. Anesthetized animals (n = 60, 15/group, 37.7 +/- 2.5 kg) were splenectomized and instrumented. A reproducible femoral artery injury was created using a 6 mm aortic punch, and free bleeding was allowed for 45 seconds. Each hemostatic agent was applied twice with three-minute compressions. All products were applied on actively bleeding wounds through a pool of blood. Fluid resuscitation was started with the first compression and titrated to a mean pressure of 65 mm Hg. Animals were observed for 180 minutes or until death. Endpoints were percent survival, survival time, blood loss, resuscitation volume, wound temperatures and tissue histology. Data are expressed as mean +/- SD and analyzed by Fisher's exact, logrank, and nonparametric ANOVA tests.

RESULTS

Baseline physiologic parameters were similar among groups. AFB did not produce hemostasis. QC also showed no hemostatic benefit, and QC treatment markedly increased maximum wound temperatures to an average of 70.8 +/- 4.2 degrees C (p < 0.001). CD stopped bleeding temporarily in only one animal. There were no survivors in the AFB, QC, or CD groups. CD numerically prolonged survival time (58.9 +/- 21.1 minute) compared with the control (38.4 +/- 24.7 minutes, p = 0.045) but the difference was not significant. FSD reduced bleeding (p < 0.05) and prevented exsanguination in 10/15 (2/3) animals, and resulted in a significantly longer average survival time (p < 0.0001).

CONCLUSION

FSD was superior to other currently utilized hemostatic products in controlling lethal arterial hemorrhage in this model of a fatal extremity wound. CD showed some hemostatic benefit. The exothermic reaction of QC was significant and resulted in gross and histologic tissue changes of unknown clinical significance. Controlled human studies with the promising products are required.

Effects of Chitosan on Human Periodontal Ligament Fibroblasts In Vitro and on Bone Formation in Rat Calvarial Defects

BACKGROUND

The purpose of this study was to evaluate the effect of chitosan on human periodontal ligament fibroblasts (hPDLF) in vitro and on bone formation in rat calvarial defects in vivo.

METHODS

Fibroblast populations were obtained from individuals with a healthy periodontium and cultured in alpha minimum essential medium (MEM) for the control group. For the experimental groups, cells were cultured in alpha-MEM containing chitosan at concentrations of 0.01, 0.1, 1, or 2 mg/ml. The 3-(4,5-dimethyl-thiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR) and the assay of alkaline phosphatase (ALPase) activity were performed. Eight mm calvarial critical-sized defects were created in 30 male Sprague-Dawley rats. The animals were divided into three groups of 10 animals each. The defects were treated with either chitosan/absorbable collagen sponge (ACS) or ACS alone in the experimental groups or were left untreated (surgical controls). The animals were sacrificed at 2 or 8 weeks post-surgery and the treatment outcomes were evaluated using histological and histomorphometric parameters.

RESULTS

The chitosan-induced proliferative responses of the hPDLF reached a plateau at a concentration of 0.1 mg/ml (P <0.05). When the hPDLF were stimulated with 0.1 mg/ml chitosan, both the mRNA expression of type I collagen and the ALP activity were significantly up-regulated (P <0.05). The surgical implantation of chitosan/ACS enhanced the new bone formation at 8 weeks post-surgery and the amount of new bone formation of the chitosan/ACS group was significantly greater than that of both the ACS alone group and the surgical control group (P <0.01). The new bone area and defect closure in the chitosan/ACS group were significantly greater than those in the ACS control and sham surgery control groups at 8 weeks (P <0.01). However, the chitosan/ ACS group exhibited significantly less bone density than both the ACS control and the sham surgery control group at 8 weeks (P <0.01).

CONCLUSIONS

Chitosan (0.1 mg/ml) enhanced the type I collagen synthesis and facilitated the differentiation into osteogenic cells. Chitosan reconstituted with ACS has a significant potential to accelerate the regeneration of bone in rat calvarial critical size defects.

Tissue engineering of cartilage using an injectable and adhesive chitosan-based cell-delivery vehicle

OBJECTIVE

Adult articular cartilage shows a limited intrinsic repair response to traumatic injury. To regenerate damaged cartilage, cell-assisted repair is thus viewed as a promising therapy, despite being limited by the lack of a suitable technique to deliver and retain chondrogenic cells at the defect site.

DESIGN

We have developed a cytocompatible chitosan solution that is space-filling, gels within minutes, and adheres to cartilage and bone in situ. This unique combination of properties suggested significant potential for its use as an arthroscopically injectable vehicle for cell-assisted cartilage repair. The primary goal of this study was to assess the ability of this polymer system, when loaded with primary articular chondrocytes, to support cartilage formation in vitro and in vivo. The chitosan gel was cultured in vitro, with and without chondrocytes, as well as injected subcutaneously in nude mice to form subcutaneous dorsal implants. In vitro and in vivo constructs were collectively analyzed histologically, for chondrocyte mRNA and protein expression, for biochemical levels of glycosaminoglycan, collagen, and DNA, and for mechanical properties.

RESULTS

Resulting tissue constructs revealed histochemical, biochemical and mechanical properties comparable to those observed in vitro for primary chondrocytes cultured in 2% agarose. Moreover, the gel was retained after injection into a surgically prepared, rabbit full-thickness chondral defect after 1 day in vivo, and in rabbit osteochondral defects, up to 1 week.

CONCLUSIONS

The in situ-gelling chitosan solution described here can support in vitro and in vivo accumulation of cartilage matrix by primary chondrocytes, while persisting in osteochondral defects at least 1 week in vivo.

Effect of Calcium Sulfate-Chitosan Composite: Pellet on Bone Formation in Bone Defect

The purpose of this experiment was to study the effects of chitosan, calcium sulfate, and calcium sulfate-chitosan composite pellet on the osteogenesis of defective tibia in rabbits. Eighty New Zealand white rabbits, each weighing approximately 3 to 3.5 kg, were used for this study. A 1-cm ostectomy was made on the middle of the tibia of each rabbit with the periosteum preserved. Nothing was implanted in the control group (group 1), and five chitosan pellets (60 mg/pellet) were implanted in group 1, three OsteoSet pellets (100 mg/pellet) in group 3, and four calcium sulfate-chitosan composite pellets (1 pellet, 80 mg; calcium sulfate 40 mg/pellet, chitosan 40 mg/pellet) in group 4. For each group, a radiographic study, bone mineral density test, three-point bending test, and histologic examination were performed in the second, fourth, and sixth weeks. In the radiologic study, in group 1, cortical bone was not formed even at 6 weeks. In group 2, it was observed at 6 weeks. In groups 3 and 4, cortical bone was partially seen around the fourth week. At 6 weeks, it was clearly observed on both sides, and the projection of the marrow cavity became distinctive, so bone consolidation was considered to be much progressed. The bone mineral density test and three-point bending test results appeared to be highly similar in groups 3 and 4 and in groups 2 and 1. Particularly at 6 weeks, the measures for groups 3 and 4 were statistically significant compared with those for groups 1 and 2 (P < 0.05). In histologic examination, new bone formation began to be seen at 2 weeks in all groups, but it was more active and faster in groups 3 and 4. At 6 weeks, fibrous connective tissue still remained at the center in groups 1 and 2; however, the fibrous connective tissue at the center was replaced with callus, the bony bridge was obvious, and lamellation of callus was observed more in groups 3 and 4. The results indicate that chitosan pellets, OsteoSet, and chitosan-calcium sulfate composite pellets facilitate new bone formation on defected bone, and that particularly OsteoSet and chitosan-calcium sulfate composite pellets are more effective than chitosan.

Eight-week histological analysis on the effect of chitosan on surgically created one-wall intrabony defects in beagle dogs

OBJECTIVE

To evaluate the periodontal tissue regenerative effects of a chitosan/collagen sponge applied to preclinical one-wall intrabony defects surgically created in beagle dogs.

MATERIAL AND METHODS

4 x 4 mm one-wall intrabony defects were surgically created in the bilateral maxillary first and third, and the mandibular second and fourth premolars. The surgical control group received a flap operation only, while the buffer control group was treated afterwards with a phosphate-buffered saline/collagen sponge (CS) and the chitosan group was treated with a chitosan/cs. The subjects were killed 8 weeks after the operation, and a comparative histological examination was performed.

RESULTS

The amount of junctional epithelium migration was 2.30+/-1.24 mm in the surgical control group, 1.49+/-1.25 mm in the buffer control group, and 0.26+/-0.59 mm in the chitosan group. A significant difference was exhibited only between the surgical control and the chitosan group (p<0.05). The amount of connective tissue adhesion was 0.68+/-0.60, 1.07+/-0.91, and 0.41+/-0.42 mm in the surgical control, buffer control, and the chitosan group, respectively. The amount of cementum regeneration was 1.42+/-0.49, 1.60+/-0.41, and 3.46+/-0.78 mm in the surgical control, buffer control, and the chitosan group, respectively. A significant difference was seen between the chitosan group and the rest (p<0.01). The amount of alveolar bone regeneration was 1.00+/-0.77, 1.52+/-0.37, and 2.43+/-0.44 mm in the surgical control, buffer control, and the chitosan group, respectively. A significant difference was observed between the chitosan group and the rest (p<0.05).

CONCLUSION

The results demonstrate the beneficial effect of the chitosan/cs on the one-wall intrabony defects of beagle dogs. The inhibited apical migration of epithelium and the increase in the amount of new bone and new cementum suggest the potency of chitosan in inducing periodontal tissue regeneration.