Abstract The study aimed to develop and evaluate a sulphated chitosan–vanadium pentoxide nanocomposite derived from Sepiella inermis cuttlebone as a potential antimicrobial material for oral healthcare applications, addressing the growing concern of multidrug-resistant oral pathogens. Chitin was extracted from S. inermis cuttlebone and converted to chitosan via deacetylation. Sulfation of chitosan was performed to enhance solubility and bioactivity. The resulting sulphated chitosan was combined with vanadium pentoxide under controlled stirring followed by lyophilization to produce a stable nanocomposite. The material was characterized using FTIR for functional group confirmation, SEM-EDX for surface morphology and elemental composition, and XRD for crystalline structure analysis. Antimicrobial activity was tested against Streptococcus mutans, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Characterization confirmed successful integration of vanadium pentoxide with sulphated chitosan, indicating strong structural and chemical interactions. The nanocomposite displayed uniform surface morphology, appropriate crystallinity, and distinct elemental signals of vanadium. Antimicrobial assays revealed significant inhibitory activity against all tested bacterial and fungal strains, suggesting a synergistic effect of sulphated chitosan with vanadium pentoxide. The sulphated chitosan–vanadium pentoxide nanocomposite synthesized from marine-derived resources represents an eco-friendly and biocompatible antimicrobial agent. Its strong activity against oral pathogens underscores its potential as a novel platform for preventing and managing dental caries and periodontal infections, while supporting the broader use of marine biomaterials in nanomedicine.

Keywords: Sulphated chitosan, Vanadium pentoxide, Innovation, Sepiella inermis, Antimicrobial activity, Nanocomposite

Citation:  Desai, S.S., Manogaran, Y., Duraisamy, R., Ganapathy, D., and Ramasamy, P. 2026. Biogenic sulphated chitosan - vanadium pentoxide complexes from Sepiella inermis: A potential antimicrobial agent for oral pathogens. Natural and Life Sciences Communications. 25(3): e2026043.

Graphical Abstract:

INTRODUCTION

The growing number of oral infections caused by multidrug-resistant organisms has driven the search for innovative antimicrobial medicines that are both effective and biocompatible. Streptococcus mutans, Porphyromonas gingivalis, and Candida albicans are known oral pathogens that cause dental caries, periodontitis, and oral candidiasis. These infections can damage dental health and contribute to systemic problems if left untreated (Pitaksuteepong et al., 2024; Radhakrishnan and Panicker, 2025). Marine-derived biopolymers have emerged as intriguing options for biomedical applications. They are notable for their availability, renewability, and inherent bioactivity. Among these, chitosan, a deacetylated derivative of chitin, has noteworthy antimicrobial, antioxidant, and film-forming characteristics (Rizeq et al., 2019). The cuttlebone of Sepiella inermis, a mollusc species, contains a high concentration of chitin. This chitin may be bio-converted into chitosan via alkaline treatment. This valorization of marine garbage aligns with the Sustainable Development Goals and the principles of green chemistry (Datta et al., 2024).

Chemical modification of chitosan, notably sulfation, improves its solubility and biological activity. Sulfated chitosan has a higher negative charge density. This enables stronger electrostatic interactions with positively charged microbial membranes, leading to membrane breakdown and cell death (Ardean et al., 2021). Sulfated derivatives have also shown better performance in drug delivery, gene therapy, and antimicrobial applications (Zeng et al., 2019; Kanchanomai et al., 2025). Another strategy to broaden the antimicrobial range is to incorporate metal oxides into biopolymer matrices. Vanadium pentoxide (V₂O₅), a transition metal oxide, induces oxidative stress and effectively inhibits the growth of microorganisms. Its incorporation into chitosan matrices produces hybrid nanocomposites with synergistic antimicrobial properties (Singh et al., 2021; Ganesan et al., 2025). These nanocomposites combine the bioactivity of chitosan with the redox potential of vanadium, providing a dual mode of action against pathogens.

To create biogenic sulfated chitosan-vanadium pentoxide nanocomposites, chitin from S. inermis is extracted, then deacetylated to form chitosan, sulfated, and finally incorporated with V₂O₅ through stirring and lyophilization. This approach guarantees the creation of stable nanocomposites with increased surface area and reactivity, which is critical for antimicrobial effectiveness (Al-Rajhi et al., 2024; Sarala et al., 2025). Characterization of synthesized nanocomposites is required to establish their structural integrity and functional characteristics. Fourier Transform Infrared Spectroscopy (FTIR) can identify functional groups within a molecular structure and validate the effectiveness of sulfation and metal oxide inclusion. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDX) give information about surface shape and elemental composition, while X-ray Diffraction (XRD) reveals the crystalline nature of the nanocomposites.

Recent investigations have shown that chitosan-metal oxide nanocomposites exhibit higher antimicrobial activity than their individual components. For example, chitosan-ZnO nanocomposites produced increased inhibition zones against E. coli, K. pneumoniae, S. aureus, and B. subtilis. This demonstrates the potential of such hybrid materials in combating bacterial infections (Babaei-Ghazvini et al., 2021; Kasi et al., 2025). Similarly, chitosan-V₂O₅ nanohybrids have been investigated for electrocatalytic and antimicrobial properties. These findings show their potential applicability in biological settings (Vinothini et al., 2024; Bansal et al., 2025). In summary, the development of biogenic sulfated chitosan-vanadium pentoxide nanocomposites from S. inermis holds promise for oral healthcare applications. These materials combine the benefits of marine-derived biopolymers with those of inorganic nanoparticles. They provide a powerful, long-lasting, and biocompatible alternative for treating oral infections. Further research into their mechanism of action, long-term stability, and clinical efficacy will support their use in therapeutic formulations such as mouthwashes, dental coatings, and antimicrobial gels.

MATERIALS AND METHODS

Extraction and characterization of chitosan and sulphated chitosan

Chitin was extracted from the internal bone of Sepiella inermis through demineralization, deproteinization, and deacetylation to obtain chitosan. Sulphated chitosan was synthesized using DMF dissolution, sulfation, ethanol precipitation, dialysis, and lyophilization. The product was characterized by FTIR for functional groups, SEM for morphology, and XRD for crystallinity, confirming successful structural modification (Sajith et al., 2024).

Synthesis of sulphated chitosan vanadium pentoxide nanocomposite

To make a nanocomposite, mix 0.5g of sulphated chitosan with 100 mL of distilled water, then add 0.5g of vanadium pentoxide (V₂O₅). Stir constantly, then add 5% acetic acid dropwise. Continue for 2-4 h. Mix the resulting solution with sodium tripolyphosphate and agitate for 12 h. Centrifuge for 30 min and lyophilize. Mashing the powder with a mortar and pestle yields a sulphated chitosan-vanadium pentoxide nanocomposite (Eswaran et al., 2023).

Fourier transform-infrared spectral analysis of sulphated chitosan vanadium pentoxide nanocomposite (FT-IR)

The Bruker Alpha II FTIR. A spectrum analyzer was used to test the sulphated chitosan vanadium pentoxide nanocomposite.

Scanning electron microscopy (SEM)

The surface characteristics and structure of a sulphated chitosan vanadium pentoxide nanocomposite were studied using SEM. Using the Hitachi Hus-4 vacuum vaporizer, a little quantity of gold/palladium (40/60) was added to the specimen, which quickly evaporated at 20 V. The research was conducted at differing degrees of magnification while increasing operational potential ranging from 0.5 to 30 kV.

Energy-dispersive X-ray (EDX)

The catalysts' energy-dispersive X-ray (EDX) spectra were acquired using an EDX AMETEK apparatus (Thermo Fisher Scientific Inc., Waltham, MA, USA) equipped with an octane detector and TEAM software (version 4.5, EDAX AMETEK Inc., Mahwah, NJ, USA). EDAX analysis was carried out on uncoated catalysts.

X-ray diffraction (XRD)

The Shimadzu XRD-6000 device measures XRD intensity as a function of specimen orientation and diffraction angle (2θ). Diffraction patterns were used to estimate the size and placement of the crystallites, and the specimen's crystal structure was established after a detailed investigation of its structural characteristics.

Antimicrobial activity

Three bacterial species and one fungal species were tested: Streptococcus mutans, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After preparing the nutrient broth medium, it was autoclaved for 15 min at 15 pounds of pressure. Following sterilization, each strain of bacteria was introduced separately into the nutrient broth, and the cultures were incubated at 37°C for 24 h. Muller-Hinton Agar (MHA) was produced, autoclaved under identical conditions, and placed on sterile petri plates. A sterile cotton swab was used to put the stationary-phase cultures into agar plates.

The agar well diffusion technique was used to evaluate the antimicrobial activity of sulphated chitosan vanadium pentoxide against four pathogenic pathogens (Tepe et al., 2004). After one day, sanitized Muller Hinton Agar (MHA) plates were swabbed with nutrient broth cultures of the test microorganisms. Wells, each 5 mm in diameter, were aseptically made in the contaminated plates. Three dosages of sulphated chitosan vanadium pentoxide (1.25-5 mg/ml) were added to the wells after being dissolved in the appropriate medium. Amikacin, Levofloxacin, Ciprofloxacin, and Fluconazole (1 mg/ml) served as control and standard solutions. Additionally, 0.2% distilled water was used as a control. The plates were kept upright at 37°C overnight. The inhibition zones were then evaluated.

RESULTS

FTIR spectroscopy

FTIR spectroscopy was used to investigate the chemical structure and bonding of sulphated chitosan vanadium pentoxide produced from cuttle bone. The FTIR spectra (4,000-400 cm⁻¹) were analyzed to identify functional groups, revealing high absorption bands at 3,249, 1,539, 1,066, 902, 518, 1,021, and 746 cm⁻¹ (Figure 1). Peaks at 1,021 cm⁻¹ and 746 cm⁻¹ corresponded to the vibrational mode of doubly bridged oxygen atoms (V-O-V) and the stretching of terminal vanadyl oxygen bonds (V=O), respectively. The FTIR study reveals effective chemical integration between the organic chitosan matrix and the inorganic vanadium pentoxide (V₂O₅), with characteristic absorption bands confirming the identification of functional groups and bonding interactions within the composite.

Figure 1. FTIR analysis of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

Scanning electron microscope

The SEM image of the sulphated chitosan vanadium pentoxide nanocomposite reveals accurate dimensions, morphology, topography, and spatial arrangement. The nanocomposite is mostly rod-shaped, with a granular surface morphology, and appears to be on the nanoscale (Figure 2). These features indicate effective synthesis, making it suitable for both antimicrobial and anticancer applications. The granular surface and homogeneous size distribution enable reliable performance across a wide range of applications.

Figure 2. SEM analysis of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

EDX

The EDX spectrum of sulphated chitosan vanadium pentoxide shows the presence of six important elements: vanadium, phosphorus, iron, sodium, copper, and potassium. Vanadium dominates the composition, accounting for the largest weight (28.26%) and atomic percentage (44.18%), thereby demonstrating its importance (Figure 3). Sodium and Phosphorus also have significant atomic percentages, indicating their importance in the sample matrix. The spectrum peaks correspond to the energy levels associated with each element. This research shows that Vanadium contains trace quantities of other metals and nonmetals.

Figure 3. EDX analysis of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

X-ray diffraction

X-ray diffraction (XRD) analysis was performed to identify the crystalline and amorphous phases present in the materials. The XRD pattern for sulphated chitosan vanadium pentoxide was recorded in the 10°–60° (2θ) range and exhibited five distinct peaks at 2θ values of 15.40°, 20.44°, 26.38°, 30.97°, and 45.70°. The pronounced peak at 26.382° was indicative of an amorphous structure (Figure 4).

Figure 4. XRD analysis of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

Antimicrobial activity

The antimicrobial efficacy of biogenic sulphated chitosan-vanadium pentoxide nanocomposites was evaluated against key oral pathogens using the zone of inhibition assay. Lower concentrations (25 and 50 μg) did not inhibit any of the tested microorganisms. At 100 μg, the nanocomposite exhibited moderate inhibition against Pseudomonas aeruginosa (11 ± 1.25 mm) and Candida albicans (11 ± 1.25 mm), comparable to conventional antimicrobials (Figure 5). Streptococcus mutans showed an inhibitory zone of 11 ± 0.78 mm at 100 μg, whereas Staphylococcus aureus remained unresponsive at all concentrations (Table 1). These results suggest concentration-dependent antimicrobial activity, particularly against fungal and Gram-negative organisms.

Figure 5. Antimicrobial activity of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

Table 1. Antimicrobial activity of sulphated chitosan vanadium pentoxide nanocomposite from Sepiella inermis.

DISCUSSION

Vanadium pentoxide and chitosan-based structures inside the composite are clearly visible in the FTIR spectrum. The peak at 746 cm⁻¹ corresponds to the stretching vibration of terminal vanadyl oxygen bonds (V=O), while the band at 1,021 cm⁻¹ shows doubly coordinated oxygen bonds (V-O-V). These findings align with the normal V=O stretching near 1,030 cm⁻¹, V-O-V symmetric stretching about 508 cm⁻¹, and asymmetric stretching at 770 cm⁻¹ vibration modes of V₂O₅ nanoparticles (Subramanian and David, 2024). Further research has confirmed the existence of vanadium oxide structures in the synthesized material by reporting V=O stretching at 1,022 cm⁻¹ and V-O-V deformation at 817 cm⁻¹ and 580 cm⁻¹ (Kurganskii et al., 2003; Sridhar et al., 2016).

Hydroxyl (-OH) groups, which are typical of polysaccharide structures like chitosan, are indicated by the broad absorption band at 3,249 cm⁻¹. This is consistent with Doryteuthis singhalensis sulfated chitosan spectra, which revealed peaks between 3,428 and 470 cm⁻¹ (Dhahri et al., 2010; Ben Mansour et al., 2017). Absorption bands at 3,395 cm⁻¹ (O-H stretching) and 2,923 cm⁻¹ (C-H stretching) show the hydroxyl and C-H bonds that chitosan's sugar ring contributes (Han et al., 2016). C=O stretching vibrations, a characteristic frequently seen in sulfated chitosan, are suggested by the peak at 1,539 cm⁻¹. Ulva pertusa derivatives have been shown to have similar peaks at 1,610 cm⁻¹ (Duarte et al., 2002; Vikhoreva et al., 2005). Absorption bands at 1,066 cm⁻¹ and 902 cm⁻¹ (S=O stretching and C-O-S links) verify the presence of sulfo groups. Due to sulfo group incorporation and N-S=O asymmetric stretching, sulfur-treated chitosan showed peaks at 669.30 cm⁻¹ and 1,161.64 cm⁻¹ (Yen et al., 2009). Donax scortum chitosan was found to have similar sulfur-based functional groups (Qin, 1993).

Similar to the symmetric stretch at 508 cm⁻¹ in V₂O₅ nanoparticles, the peak at 518 cm⁻¹ represents V-O-V bending vibrations (Subramanian and David, 2024). A complicated bonding environment comprising C-O-C (ether), C-OH (alcohol), and sulfo (S=O) vibrations is shown by overlapping bands in the 1,000–1,200 cm⁻¹ area. In line with the functional groups found here, sulfated chitosan from S. inermis showed peaks at 993 cm⁻¹, 1,160 cm⁻¹, 1,376 cm⁻¹, and 1,651 cm⁻¹ (Sajith et al., 2024).

The sulphated chitosan–vanadium pentoxide nanocomposite adopts a rod-shaped morphology with a granular surface, demonstrating its nanoscale nature, according to SEM examination. Surface responsiveness is improved by this granular texture, which is essential for biological applications. Sulfated chitosan from S. inermis creates fibril-like structures (Sajith et al., 2024), whereas V₂O₅ nanoparticles are usually sponge-like and vary from 40–50 nm (Subramanian and David, 2024). There have been reports of similar fibril morphologies in Sepia kobiensis chitosan (Ramasamy et al., 2014) and Doryteuthis singhalensis (Ramasamy et al., 2017). The composite's observed shift from fibril to granular shape points to increased biological performance and mechanical stability. Effective cellular contacts, regulated release, and consistent functionality are further supported by homogeneous nanoparticle distribution.

With vanadium making up 44.18% of the atomic composition, EDX verified the composite's high vanadium content. Matrix complexity is influenced by trace elements like potassium, copper, iron, sodium, and phosphorus. These results are in line with previous studies of concentrations of oxygen and vanadium of 28.33% and 10.45%, respectively (Ganeshan et al., 2016). The selective elemental incorporation seen here is corroborated by thin-film EDX spectra that showed selective incorporation of Zn, V, and O (Nagaraju et al., 2019).

According to Ashour and El-Sayed (2009), XRD examination showed a significant (001) peak, indicating a preferred orientation with the crystallographic c-axis perpendicular to the substrate. With a prominent amorphous peak at 26.382°, the composite showed five peaks between 10° and 60° (2θ), indicating a mostly non-crystalline structure. On the other hand, cuttlefish chitosan had a peak at 20.7°, whereas pure chitosan displayed crystalline peaks at 2θ = 9.8° and 20.8° (Drozd et al., 2001). According to Sajith et al. (2024), sulfated chitosan usually shows little peaks between 20° and 30°. According to Subramanian and David (2024), V₂O₅ nanoparticles in comparable composites have crystallite diameters ranging from 33.72 to 52.78 nm. Even though the matrix is amorphous, the sulphated chitosan makes it easier for V₂O₅ nanoparticles to align well.

The biogenic sulphated chitosan–vanadium pentoxide nanocomposite showed dose-dependent antibacterial efficacy against Streptococcus mutans, Candida albicans, and Pseudomonas aeruginosa. It's interesting to note that Staphylococcus aureus remained resistant, in contrast to previous research where Bacillus cereus and S. aureus were somewhat inhibited by V₂O₅ nanoparticles at 100 μg (Subramanian and David, 2024). According to earlier research, V₂O₅ exhibited antifungal efficacy at 50 μg (Sridhar et al., 2016), indicating that the biogenic matrix affects antibacterial potency. Gram-negative bacteria (E. coli, Serratia marcescens) are typically less vulnerable to the disruption of bacterial cell walls caused by chitosan derivatives than Gram-positive species (S. aureus, B. subtilis) (Vilar Junior et al., 2016). Structural or compositional differences in the nanocomposite may be the cause of the observed S. aureus resistance, underscoring the need for more tuning to improve performance.

CONCLUSIONS

The current work describes the effective production and assessment of biogenic sulphated chitosan-vanadium pentoxide nanocomposites. These were obtained from S. inermis and studied as potential antimicrobial agents against oral infections. A new hybrid material with potential therapeutic applications in oral healthcare was developed. The process leveraged the natural abundance of chitin in cuttlebone and enhanced its bioactivity through sulfation and integration of vanadium pentoxide. Characterization methods included FTIR, SEM-EDX, and XRD. These validated the nanocomposite's structural integrity and formation. Antimicrobial tests demonstrated dose-dependent effectiveness. Considerable inhibitory zones were detected against Streptococcus mutans, Pseudomonas aeruginosa, and Candida albicans at higher doses (100 μg). Notably, Staphylococcus aureus remained resistant, suggesting selective antimicrobial activity. The results indicate that the nanocomposite breaks microbial membranes and causes oxidative stress, likely due to the synergistic interaction of sulphated chitosan and vanadium pentoxide.

The use of marine-derived biopolymers not only promotes the creation of sustainable materials but also supports the development of environmentally friendly products. It also adheres to the principles of green chemistry. Chitosan-based materials exhibit biocompatibility and low cytotoxicity, making them an ideal choice for oral applications. These include antimicrobial coatings, dental gels, and therapeutic rinses. Furthermore, this method specifically suppresses harmful bacteria without altering the healthy oral flora, thereby emphasizing its therapeutic utility. In conclusion, the biogenic sulphated chitosan-vanadium pentoxide nanocomposite is effective, environmentally friendly, and biocompatible for treating oral infections. Future research should focus on in vivo validation, formulation development, and long-term stability. This would aid clinical translation. This research lays a foundation for using marine biopolymers and metal oxides in next-generation oral therapies. It provides a long-term solution to the growing problem of antimicrobial resistance in tooth infections.

ACKNOWLEDGEMENTS

The authors are thankful to the Department of Prosthodontics & Implantology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University Chennai, Tamil Nadu, for providing the necessary facilities and support.

AUTHOR CONTRIBUTION

Shreya Sachin Desai and Yagniyasree Manogaran: Conceptualization (Supporting), Methodology (Equal), Software (Lead), Validation (Lead), Formal Analysis (Equal), Investigation (Equal), Resources (Lead), Data Curation (Lead), Writing – Original Draft (Lead), Visualization (Lead); Revathi Duraisamy: Conceptualization (Supporting), Methodology (Equal), Writing – Review & Editing (Supporting); Dhanraj Ganapathy: Conceptualization (Equal), Methodology (Equal), Writing – Review & Editing (Equal); Pasiyappazham Ramasamy: Conceptualization (Lead), Methodology (Equal), Software (Supporting), Validation (Supporting), Formal Analysis (Equal), Investigation (Lead), Writing – Review & Editing (Lead), Supervision (Lead), Project Administration (Lead), Funding Acquisition (Lead).

DECLARATION OF INTEREST

The authors declare no competing financial interests or personal relationships that could influence the work reported in this study.

REFERENCES

Al-Rajhi, A.M., Abdelghany, T.M., Almuhayawi, M.S., Alruhaili, M.H., Al Jaouni, S.K., and Selim, S. 2024. The green approach of chitosan/Fe₂O₃/ZnO-nanocomposite synthesis with an evaluation of its biological activities. Applied Biological Chemistry. 67(1): 75. https://doi.org/10.1186/s13765-024-00926-2

Ardean, C., Davidescu, C.M., Nemeş, N.S., Negrea, A., Ciopec, M., Duteanu, N., and Musta, V. 2021. Factors influencing the antibacterial activity of chitosan and chitosan modified by functionalization. International Journal of Molecular Sciences. 22(14): 7449.  https://doi.org/10.3390/ijms22147449

Ashour, A. and El-Sayed, N.Z. 2009. Physical properties of V₂O₅ sprayed films. Journal of Optoelectronics and Advanced Materials. 11: 251-256.

Babaei-Ghazvini, A., Acharya, B., and Korber, D.R. 2021. Antimicrobial biodegradable food packaging based on chitosan and metal/metal-oxide bio-nanocomposites: A review. Polymers. 13(16): 2790. https://doi.org/10.3390/polym13162790

Bansal, S., Tomer, A., Singh, A., Tyagi, N., Kushwaha, H.R., and Jain, P. 2025. In-vitro assay studies and molecular docking of functionalized chitosan decorated vanadium pentoxide nano-agents as an antidiabetic drug. International Journal of Biological Macromolecules. 298: 139986. https://doi.org/10.1016/j.ijbiomac.2025.139986

Ben Mansour, M., Balti, R., Ollivier, V., Ben Jannet, H., Chaubet, F., and Maaroufi, R.M. 2017. Characterization and anticoagulant activity of a fucosylated chondroitin sulfate with unusually procoagulant effect from sea cucumber. Carbohydrate Polymers. 174: 760-771. https://doi.org/10.1016/j.carbpol.2017.06.128

Datta, D., Sarkar, S., Biswas, S., Mandal, E., and Das, B. 2024. Valorization of marine waste towards the production of high-value-added products, bioplastics, and other industrial applications. In: Mandal, S., Das, B., editors. Multidisciplinary applications of marine resources: A step towards green and sustainable future. Singapore (SG): Springer Nature Singapore. p 161–185. https://doi.org/10.1007/978-981-97-5057-3_8

Dhahri, M., Mansour, M.B., Bertholon, I. Ollivier, V.C, Boughattas, N.A., Hassine, M., Jandrot-Perrus, M.C., Chaubet, F.C., and Maaroufi, R.M. 2010. Anticoagulant activity of a dermatan sulfate from the skin of the shark Scyliorhinus canicula. Blood Coagulation & Fibrinolysis. 21: 547-557. https://doi.org/10.1097/MBC.0b013e32833b643b

Drozd, N.N., Sher, A.I., Makarov, V.A., Galbraikh, L.S., Vikhoreva, G.A., and Gorbachiova, I.N. 2001. Comparison of antithrombin activity of the polysulphate chitosan derivatives in in vivo and in vitro system. Thrombosis Research. 102: 445-455. https://doi.org/10.1016/s0049-3848(01)00266-3

Duarte, M.L., Ferreira, M.C., Marvao, M.R., and Rocha, J. 2002. An optimised method to determine the degree of acetylation of chitin and chitosan by FTIR spectroscopy. International Journal of Biological Macromolecules. 31: 1-8. https://doi.org/10.1016/S0141-8130(02)00039-9

Eswaran, A., Subramanian, R., Sivasubramanian, G., and Gurusamy, A. 2023. Chitosan nanoparticle-montmorillonite-titanium dioxide nanocomposites: Synthesis, characterization, and antimicrobial activity. Iranian Journal of Chemistry and Chemical Engineering. 42(1): 19-26. https:/doi.org/10.30492/ijcce.2022.539868.4951

Ganesan, M., Chinnuraj, I.P., Rajendran, R., Rojviroon, T., Rojviroon, O., Thangavelu, P., and Sirivithayapakorn, S. 2025. Synergistic enhancement for photocatalytic and antibacterial properties of vanadium pentoxide (V₂O₅) nanocomposite supported on multi-walled carbon nanotubes. Journal of Cluster Science. 36: 75. https://doi.org/10.1007/s10876-025-02795-1 

Ganeshan, S., Ramasundari, P., Elangovan, A., and Vijayalakshmi, R. 2016. Optical and structural studies of vanadium pentoxide thin films. Nanosystems: Physics, Chemistry, Mathematics. 7(4): 687-690. https://doi.org/10.17586/2220-8054-2016-7-4-687-690

Han, Z., Zeng, Y., Zhang, M., Zhang, Y., and Zhang, L. 2016. Monosaccharide compositions of sulfated chitosans obtained by analysis of nitrous acid degraded and pyrazolone-labeled products. Carbohydrate Polymers. 136: 376-383. https://doi.org/10.1016/j.carbpol.2015.07.087

Kanchanomai, V., Chaijareenont, P., Wanachantararak, P., and Silthampitag, P. 2025. Effect of chitosan oligosaccharide in denture adhesive on the inhibition of Candida albicans and adhesive strength to heat-cured polymethylmethacrylate. Natural and Life Sciences Communications. 24(4): e2025067. https://doi.org/10.12982/NLSC.2025.067

Kasi, G., Venkatachalam, B., Thanakkasaranee, S., Stalin, N., Dharmaraj, R., Jantanasakulwong, K., and Rachtanapun, P. 2025. Green synthesis of silver nanoparticles using Curcuma longa: Evaluation of antimicrobial activity, in vivo imaging-based toxicity, and in vitro biocompatibility. Natural and Life Sciences Communications. 24(4): e2025060. https://doi.org/10.12982/NLSC.2025.060

Kurganskii, S.I., Pereslavtseva, N.S., and Levitskaya, E.V. 2003. Fermi surface and electrical characteristics of molybdenum disilicide. Physics of the Solid State. 45(2): 201-206. https://doi.org/10.1134/1.1553518

Nagaraju, P., Vijayakumar, Y., Reddy, M.R., and Deshpande, U.P. 2019. Effect of vanadium pentoxide concentration in ZnO/V₂O₅ nanostructured composite thin films for toluene detection. The Royal Society of Chemistry. 9(29): 16515-16524. https://doi.org/10.1039/C9RA02356A

Pitaksuteepong, T., Chatthong, A., Meepian, A., and Jobsri, J. 2024. Development of toothpaste containing morus alba stem extract and its antimicrobial activity against oral pathogens. Natural and Life Sciences Communications. 23(4): e2024060. https://doi.org/10.12982/NLSC.2024.060

Qin, Y. 1993. The chelating properties of chitosan fibers. Journal of Applied Polymer Science. 49: 727-731. https://doi.org/10.1002/app.1993.070490418

 Radhakrishnan, A. and Panicker, U.G. 2025. Sustainable chitosan-based biomaterials for the future: A review. Polymer Bulletin. 82(3): 661-709. https://doi.org/10.1007/s00289-024-05561-x

Ramasamy, P., Subhapradha, N., Shanmugam, V., and Shanmugam, A. 2014. Extraction, characterization and antioxidant property of chitosan from cuttlebone Sepia kobiensis (Hoyle 1885). International Journal of Biological Macromolecules. 64: 202-212. https://doi.org/10.1016/j.ijbiomac.2013.12.008

Ramasamy, P., Subhapradha, N., Thinesh, T., Selvin, J., Selvan, K.M., Shanmugam, V., and Shanmugam, A. 2017. Characterization of bioactive chitosan and sulfated chitosan from Doryteuthis singhalensis (Ortmann, 1891). International Journal of Biological Macromolecules. 99: 682-691. https://doi.org/10.1016/j.ijbiomac.2017.03.041

Rizeq, B.R., Younes, N.N., Rasool, K., and Nasrallah, G.K. 2019. Synthesis, bioapplications, and toxicity evaluation of chitosan-based nanoparticles. International Journal of Molecular Sciences. 20(22): 5776. https://doi.org/10.3390/ijms20225776

 Sajith, M.P., Pitchai, A., Ramasamy, P., and Sajith Jr, M.P. 2024. Anticoagulant protective effects of sulfated chitosan derived from the internal bone of spineless cuttlefish (Sepiella inermis). Cureus. 16(7): e64558. https://doi.org/10.7759/cureus.64558

Sarala, S., Karthik, P., Sasikala, V., Prakash, N., and Mukkannan, A. 2025. V₂O₅-doped NiFe-layered double hydroxides: Bifunctional catalysts for energy and environmental remediation. Research on Chemical Intermediates. 51(6): 2955-2979. https://doi.org/10.1007/s11164-025-05582-9

Singh, J., Singh, K.R., Kumar, M., Verma, R., Verma, R., Malik, P., and Kumar, D. 2021. Melt-quenched vanadium pentoxide-stabilized chitosan nanohybrids for efficient hydrazine detection. Materials Advances. 2(20): 6665-6675. https://doi.org/10.1039/D1MA00619C

Sridhar, C., Yernale, N.G., and Prasad, M.A. 2016. Synthesis, spectral characterization, and antibacterial and antifungal studies of PANI/V₂O₅ nanocomposites. International Journal of Chemical Engineering. 2016(1): 3479248. https://doi.org/10.1155/2016/3479248

Subramanian, P. and David, S.A. 2024. Antibacterial activity of V₂O₅ nanoparticles. Uttar Pradesh Journal of Zoology. 45(20): 446-450. https://doi.org/10.56557/upjoz/2024/v45i204600

Tepe, B., Donmez, E., Unlu, M., Candan, F., Daferera, D., Vardar-Unlu, G., and Sokmen, A., 2004. Antimicrobial and antioxidative activities of the essential oils and methanol extracts of Salvia cryptantha (Montbret et Aucher ex Benth.) and Salvia multicaulis (Vahl). Food Chemistry. 84(4): 519-525. https://doi.org/10.1016/S0308-8146(03)00267-X

Vikhoreva, G., Bannikova, G., Stolbushkina, P., Panov, A., Drozd, N., Makarov, V., Varlamov, V., and Gal'braikh, L. 2005. Preparation and anticoagulant activity of a low-molecular weight sulfated chitosan. Carbohydrate Polymers. 62: 327-332. https://doi.org/10.1016/j.carbpol.2005.05.022

Vilar Junior, J.C., Ribeaux, D.R., Alves da Silva, C.A., Campos-Takaki, D., and Maria, G. 2016. Physicochemical and antibacterial properties of chitosan extracted from waste shrimp shells. International Journal of Microbiology. 2016(1): 5127515. https://doi.org/10.1155/2016/5127515

Vinothini, A., Conceptulaization, A.M., Arulkumar, E., Vedhi, C., and Thanikaikarasan, S. 2024. Green route synthesis of transition metal doped V₂O₅ nanoparticles, with emerging biomedical applications. Results in Chemistry. 7: 101373. https://doi.org/10.1016/j.rechem.2024.101373

Yen, M.T., Yang, J.H., and Mau, J.L. 2009. Physicochemical characterization of chitin and chitosan from crab shells. Carbohydrate Polymers. 75: 15-21.   https://doi.org/10.1016/j.carbpol.2008.06.006

Zeng, K., Groth, T., and Zhang, K. 2019. Recent advances in artificially sulfated polysaccharides for applications in cell growth and differentiation, drug delivery, and tissue engineering. ChemBioChem. 20(6): 737-746. https://doi.org/10.1002/cbic.201800569

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