3D Printed Film Containing Rhodomyrtus tomentosa Leaves Extract for Antibacterial,Anti-Inflammatory and Antioxidant Applications

Abstract

Background: Macroporous gels containing essential oil (EO) from Cinnamomum bejolghota have emerged as promising materials for biomedical applications due to the combinatory benefits of a highly porous structure and the bioactive properties of natural extracts. Objectives: Therefore, this study develops a 3D printed macroporous gel incorporating EO from C. bejolghota leaf extract by using freeze-thaw method to create interconnected pores. Methods: The gel samples were prepared by mixing agar with the EO at various concentrations (50, 100, and 200 µmol/L) and freezing at −20 °C to form the porous network. The as-synthesized gel was subjected to SEM and FTIR analysis, then investigated for antibacterial and anti-inflammatory activities. Results: The SEM images revealed that the pore sizes ranged from 1 to 2 µm, with the successful integration of EO. Specifically, the macroporous gel sample containing C. bejolghota leaves EO at 200 µmol/L (Agar/EO200) exhibited the most significant antibacterial action against E. coli and S. aureus, as indicated by inhibition zones radius of 6.3 ± 0.26 mm and 8.7 ± 0.94 mm, respectively. Additionally, the anti-inflammatory activity of Agar/EO200 achieved 86.01% ± 0.43 nitric oxide (NO) inhibition, which outweighed other samples. Conclusion: These results suggest that the macroporous gel holds great potential as a multi-functional material for wound healing and other biomedical applications.

Keywords

macroporous gels essential oil antibacterial anti-inflammatory wound healing

Introduction

Macroporous gels are a unique class of materials characterized by their three-dimensional network structure with interconnected macropores, typically larger than 50 nanometers in diameter.^1,2 As compared to traditional hydrogels, macroporous gels possess interconnected porous architecture that provide several distinct advantages (eg increased surface area) for various applications in the biomedical field, particularly drug delivery, tissue engineering, and bio-sensing.^3–5 For example, in the study of Tokuyama et al, the large surface area facilitates higher loading capacities of therapeutic agents, thus ensuring sustained and controlled release.³ This characteristic is crucial for maintaining therapeutic levels of drugs over extended periods, thus enhancing treatment efficacy, as well as reducing the frequency of administration. In tissue engineering, the macroporous structure of these gels plays a vital role in promoting cell infiltration and tissue integration. The interconnected pores mimic the extracellular matrix of natural tissues to provide a conducive environment for cell growth, differentiation, and nutrient transport that are is essential for the development of scaffolds that support the regeneration of damaged tissues or organs.^6–8 In addition, macroporous gels can be designed to degrade at controlled rates to match the pace of new tissue formation and minimize the need for surgical removal after fulfilling their purpose.

Cinnamomum bejolghota (Lauraceae family), is a plant of significant ethnobotanical and medicinal importance, especially in various Asian cultures. The leaves of this plant are traditionally used in numerous therapeutic applications due to their rich phytochemical composition.⁴ C. bejolghota leaves extract has garnered scientific interest owing to their broad spectrum of biological activities, including antibacterial, anti-inflammatory, and antioxidant properties.^5,9 The bioactive constituents of C. bejolghota leaves extract which are responsible for the plant's potent medicinal properties include EOs, tannins, flavonoids, and phenolic compounds.^6,7 In particular, the EO extracted from C. bejolghota leaves primarily compose of cinnamaldehyde, eugenol, and camphor which exhibit strong antibacterial activity by disrupting bacterial cell walls and membranes, leading to cell lysis and death.^8–10 Thus, C. bejolghota leaves EO can be considered as a promising natural alternative agent to synthetic antibiotics to avoid antibiotic resistance.

In addition to their antibacterial effects, the EO of C. bejolghota leaves also exhibit significant anti-inflammatory properties. Inflammation is a biological response to harmful stimuli such as pathogens, damaged cells, or irritants. Although it is a protective mechanism, chronic inflammation can lead to various diseases, including arthritis, cardiovascular diseases, and cancer. The anti-inflammatory activity of C. bejolghota is primarily attributed to their flavonoid content which inhibits the production of pro-inflammatory mediators such as nitric oxide, prostaglandins, and cytokines.¹¹ This modulation of inflammatory pathways helps reduce swelling, pain, and tissue damage, thereby providing a natural remedy for inflammatory conditions. The antioxidant properties of C. bejolghota leaves are another crucial aspect of their medicinal potential. Antioxidants are compounds that inhibit oxidation reaction that can produce free radicals and cause cellular damage. The phenolic compounds in the leaves, such as quercetin and kaempferol, are able to neutralize free radicals, thereby preventing oxidative stress and its associated cellular damage.^11,12 This activity is particularly beneficial in preventing oxidative stress and chronic diseases such as cancer, neurodegenerative disorders, and cardiovascular diseases.

Despite the extensive research on macroporous gels and their biomedical applications, there remains a lack of studies which integrate natural bioactive compounds like C. bejolghota EO into macroporous gel. Previous studies primarily focused on synthetic antibacterial agents and single-function hydrogels, neglecting the combined benefits of multifunctional natural extracts that possess antibacterial, anti-inflammatory, and antioxidant properties. Moreover, research addressing the controlled and sustained release of bioactive compounds within macroporous structure remained limitedly known. The incorporation of C. bejolghota EO into a macroporous gel offers a novel approach to overcome these challenges, enhancing therapeutic efficacy while maintaining biocompatibility and sustainability.

Therefore, the present study aims to develop a 3D printed macroporous gel incorporating EO from C. bejolghota leaf extract. The antibacterial, anti-inflammatory, and antioxidant properties of the gel were evaluated for potential applications, offering a multi-functional and naturally derived alternative for biomedical use.

Materials and Methods

Preparation of Materials, Chemicals and Reagents

A total weight of 5 kg of C. bejolghota leaves at the mature stage (neither too young nor too old), around 2-3 months after developing full size were collected from a local orchard in Phu Luong, Dinh Hoa district, Thai Nguyen province, Vietnam. The leaves were in good condition, with dark green color and no damage harvested directly from the middle branches of the tree. The leaves were immediately transported to the lab at the Institute of Natural Products Chemistry, VAST, Hanoi. There, the leaves were rinsed thoroughly with distilled water, dried at 30 °C for 48 h, and stored in sealed plastic bags in a cool, dry place, away from direct light, to preserve their quality for further experiments. Mueller-Hinton broth (MHB) and agar powder (MHA), nanocrystalline cellulose (purity of 92%), and anhydrous sodium sulfate (Na₂SO₄) was purchased from Sigma Aldrich (St. Louis, Missouri, USA). All chemicals and reagents were used of analytical grade.

Methods

Extraction of EO

To extract EO from C. bejolghota leaves, 500 g of dried leaves was ground by using a mortar and pestle and added with 700 mL of distilled water. Then, the mixture was heated to boiling and continue the distillation for about 3 h. The distillate was collected to a separator funnel and allowed to stand until the oil separated from the water layer. The EO layer was carefully collected and dehydrated with anhydrous Na₂SO₄ to remove excessive water. Finally, the obtained EO was stored in dark glass vials to avoid sunlight and oxidation.

Fabrication of Macroporous gel

Fabrication of macroporous gel containing EO and agar was performed as previously described by Ewa Jakubczyk et al¹³ Briefly, 2 g of agar powder was dissolved in 90 mL of distilled water, heated and stirred continuously until the agar was fully dissolved. A total of 20 mL suspension of nano-cellulose was sonicated for 5 min, then added with 10 mL of EOs at 3 concentration levels (50 µmol/L, 100 µmol/L and 200 µmol/L) to form oil mixtures. The oil mixture (10 mL) was added to the hot agar solution, and stirred well to ensure even distribution. 10 mL of the agar-oil mixture was poured into each container, and immediately placed the molds in a freezer set to −20 °C. Allow the solution to freeze completely for 4-6 h. After freezing, the gels were kept at −20 °C for an additional 12 h to ensure the formation of a stable polymer network around the frozen oil droplets. The gels were thawed at room temperature (approximately 20 °C) to melt the ice crystals and form a porous structure filled with the dispersed oil. The gels were rinsed with 50 mL of distilled water to remove any surface residues, and then dried at room temperature. A schematic diagram of the process is presented in Figure 1.

Figure 1.

The schematic diagram of cryogel formation. First, an aqueous solution containing cryo-gel precursors, monomers, and crosslinkers is cooled to −20 °C, forming ice crystals. Then, crosslinking occurs, creating a polymer network around the ice crystals. Finally, the temperature is raised to 20 °C to allow the ice to melt, leaving a porous structure.

Scanning Electron Microscopy (SEM)

SEM analysis of the as-synthesized C. bejolghota EO-containing macroporous gel were taken using a FE-SEM S4800 device (Hitachi, Japan), following the previous procedure described by Prodan et al (2013).¹⁴ The gel samples were coated with a silver thin layer to increase the conductivity.

Infrared (IR) Spectroscopy

The IR spectroscopy technique was utilized to analyze the functional groups of the as-synthesized C. bejolghota EO-containing macroporous gel EO.¹⁵ The IR spectra of samples were recorded using a Nicolet iS10 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) with the attenuated total reflection technique in the wavenumber range of 4000-400 cm⁻¹ and a resolution of 8 cm⁻¹ and 32 scans.

Antibacterial Activity

The antibacterial activity of the macroporous gel containing C. bejolghota leaf EO was evaluated using the agar well diffusion method against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Bacillus cereus (ATCC 11778), as previously described by Mustarichie, Sulistyaningsih, and Runadi.¹⁶ The bacterial strains were obtained from Vinmed Hospital (Hanoi, Vietnam). Before conducting the experiment, the bacteria were cultured in MHB at 37 °C with shaking at 150 rpm for 18-24 h to reach the exponential growth phase. The bacterial suspensions were adjusted to a concentration of approximately 10⁸ CFU/mL (equivalent to 0.5 McFarland standard). For the antibacterial assay, 100 µL of each bacterial suspension was evenly spread onto MHA plates.

The antibacterial activity of the obtained C. bejolghota leaves EO was investigated at 3 concentrations: 70 µmol/L (N-1), 100 µmol/L (N-2), and 250 µmol/L (N-3). The macroporous gel samples were cut into pieces of 1 cm² in area, then each piece was placed onto the inoculated agar plates. The test samples included three gel formulations designated as Agar/EO50, Agar/EO100 and Agar/EO200 containing EO at concentrations of 50 µmol/L, 100 µmol/L, and 200 µmol/L, respectively. The plates were incubated at 4 °C for 4 h, followed by incubation at 37 °C for 24 h. After incubation, the radius of inhibition zones formed around each sample were measured. Positive control was 0.5 µg/mL ampicillin, negative controls were 50 and 250 µg/mL camphene and sterile distilled water. All experiments were performed in triplicates.

Anti-Inflammatory Activity

The anti-inflammatory activity of C. bejolghota leaves EO and the EO-containing macroporous gel samples was evaluated by the ability to inhibit nitric oxide production in RAW264.7 macrophage cell line, as previously described by Abdelwahab et al (2011) with slight modifications.¹⁷ To check the anti-inflammatory activity of C. bejolghota leaves EO, distilled water was used as the negative control, while ampicillin at a concentration of 50 µg/mL served as the positive control. The petri dishes containing RAW264.7 cells were added 50 µL EO at the concentrations of 70 µg/mL (N-1), 100 µg/mL (N-2), and 250 µg/mL (N-3), while camphene, which is a known anti-inflammatory compound, was tested at concentrations of 50 and 250 µg/mL. Then, the dishes were incubated in incubator at 37 °C 5% CO₂.

The anti-inflammatory properties of the macroporous gel (Agar/EO) were also evaluated using distilled water as negative control and cardamonin at 3.0 µmol/L concentration as positive control. There are three concentrations (50 µg/mL,100 µg/mL, and 200 µg/mL (N-3)) of Agar/EO, with each concentration 50 µL was used. After incubation, the supernatant from each well was mixed with the Griess reagent, and absorbance was measured at 540 nm to determine NO levels.

Data Analysis

Statistical analysis was performed using Origin 2021 software (Northampton, MA, USA). All experiments were performed in triplicates and results were expressed as mean ± standard deviation (SD). Differences between groups were analyzed using one-way ANOVA followed by Tukey's post hoc test. P-value < .05 was considered statistically significant.

Results and Discussion

Extraction of EO from C. bejolghota

The obtained EO is viscous, slightly yellow in color, and has a characteristic aroma. The yield of C. bejolghota bark EO obtained is 0.622%. The EO content in this study's sample is lower compared to previously studied bark samples in Northeast India (0.810%),¹⁸ Thailand (1.01%),⁹ and Xuan Son National Park, Vietnam (1.1%).¹⁹ This difference may be due to variations in geographic location and harvest time.

Previously, the EO of C. bejolghota was analyzed using GC-MS. The analysis results show that 46 volatile components, accounting for 77.31% of the EO, were detected. Among them, 40 compounds were identified, constituting 49.26%, while 6 compounds remained unidentified, making up 28.05%. The identified compounds can be divided into five groups: 7 monoterpene hydrocarbons (9.39%), 16 oxygenated monoterpenes (17.65%), 14 sesquiterpene hydrocarbons (8.19%), 2 oxygenated sesquiterpenes (6.49%), and 1 benzenoid (7.54%). Among the identified components, the most dominant compound is myristicin (7.54%), followed by camphene (5.87%), borneol (5.62%), furopelargone A (4.64%), camphor (3.29%), 1,8-cineole (2.30%), and α-pinene (2.08%). Other compounds are present in amounts less than 2%.

The EO in this study shares similarities in composition with previous studies but differs in the content of individual compounds. Recently, in the study by Gogoi et al, α-terpineol (18.57%), α-cubebene (12.75%), linalool (7.76%), and terpinen-4-ol (5.64%) were the main components in C. bejolghota bark EO from Assam, India.¹⁸ Atiphasaworn et al identified the main components in C. bejolghota bark EO from Thailand as 1,8-cineole (40.24%), γ-terpineol (15.41%), borneol (7.86%), terpinen-4-ol (7.55%), and α-pinene (6.58%).⁵ Meanwhile, geraniol (26.2%), 1,8-cineole (24.73%), α-terpineol (9.30%), and terpinene-4-ol (3.90%) were the main components in C. bejolghota bark EO from Xuan Son National Park, Vietnam.¹⁹ Other studies have noted the presence of (E)-nerolidol²⁰ and p-cymene²¹ as major components in C. bejolghota bark EO. Differences in extraction techniques may affect the generation of various volatile compounds.²² Furthermore, the interaction between plants and their environment through the secretion and biosynthesis of secondary metabolites can alter the composition and content of EO compounds.²³ Compounds in C. bejolghota have demonstrated several biological activities, such as linalool and camphor, reduced blood pressure by inhibiting angiotensin-converting enzymes at 5 μg/mL of concentration with inhibition rates of 77.1% and 85.1%, respectively; terpinen-4-ol exhibiting anti-inflammatory properties by reducing tumor necrosis factor and interleukin-1ß; and 1,8-cineole showing effective anti-inflammatory activity.¹⁸ Therefore, the EO of C. bejolghota also possesses excellent biological activities due to these components.

Table 1 provides an overview of the antibacterial activity of N-1, N-2 and N-3 samples against E. coli, S. aureus, and B. cereus. The antibacterial activity is measured by the zone of inhibition radius in mm, which indicates the effectiveness of the samples in inhibiting bacterial growth. The inhibition zones for the N-3 sample demonstrate significantly higher antibacterial activity compared to N-1 and N-2, likely due to the higher concentration of EO used in the test. Additionally, when compared to camphene, the ability of the EO to inhibit bacterial growth presents no significant difference from that of camphene excepted for N-3 in B. cereus results. This result re-confirms that the presence of camphene in the EO contributes to its strong antibacterial properties.^24,25

Table 1.

Antibacterial Activities of C. bejolghota EO with Different Concentrations Compared to Camphene at 50 µmol/L and 250 µmol/L of Concentrations.

Compare to the study of Atiphasaworn et al, the essential oil from C. bejolghota inhibit the activities of S.aureus and B. cereus with the zone inhibition at 7.57 ± 1.53 mm and 7.87 ± 1.94 mm, respectively.⁵ This result has no significant different with our study. Moreover, the MIC of oil against various bacterial species ranged between 31.25 and 62.50 µg/mL, that can confirm again the antibacterial properties of C. bejolghota EO.⁵

As shown in Table 2, at a concentration of 50 µmol/L, the EO extracted from C. bejolghota leaves inhibits NO by 42.03% ± 0.89, which is significantly lower compared to the positive control (ampicillin at 50 µg/mL), which exhibits 88.93% ± 0.88 inhibition (P < .05). When the concentration of EO is increased to 100 µmol/L, the NO inhibition rises to 57.09% ± 0.42, showing significant improvement compared to the 50 µmol/L treatment (P < .05). At a concentration of 250 µmol/L, the NO inhibition reaches 75.36% ± 0.91, demonstrating the highest anti-inflammatory effect among the tested concentrations. These results indicate that the anti-inflammatory activity of the EO increases with higher concentrations, showing greater inhibition of nitric oxide production. For Camphene, at a concentration of 50 µmol/L, the NO inhibition is 44.03% ± 0.59, and when the concentration is increased to 250 µmol/L, the NO inhibition reaches 72.36% ± 0.81. Furthermore, the IC50 between EO and Camphene, the concentration of EO is lower than the other one. These results show that the properties of the extracted EO are no signification different compared to those of Camphene.

Table 2.

Anti-inflammatory Activity of C. bejolghota EO at Different Concentrations Compared to Camphene at 50 µmol/L and 250 µmol/L of Concentrations.

Sample Name	Concentration (µmol/L)	NO Inhibition (%)	IC₅₀ (µg/mL)
Negative Control	–	100.0 ± 1.3
Positive control (Ampicillin)	50.0	88.93 ± 0.88
EO	70	42.03 ± 0.89*	66.04
	100	57.09 ± 0.42*
	250	75.36 ± 0.91
Camphene	50	44.03 ± 0.59	72.14
Camphene	250	72.36 ± 0.81	72.14

*P < .05 indicated significant difference.

In study of Kuttithodi et al, the essential oil extracted from Cinnamomum family also presented strong antibacterial potential for both Gram-positive and Gram-negative bacteria.²⁶ These findings suggest that EO from Cinnamomum bejolghota possess significant antibacterial and anti-inflammatory properties, particularly against E. coli, and have potential applications as natural preservatives in food and pharmaceuticals.

Fabrication of Macroporous gel

In the IR spectrum of the agar sample, characteristic peaks can be observed around 3300 cm⁻¹, corresponding to the O-H stretching vibrations, which are characteristic of hydroxyl groups in the polysaccharide structure of agar.^27–29 Additionally, a strong absorption band around 2900 cm⁻¹ indicates the C-H stretching vibrations, characteristic of the C-H bonds in the polymer chain of agar. The absorption bands in the range of 1000-1200 cm⁻¹ correspond to the C-O-C stretching vibrations, indicating the presence of ether linkages in the agar structure.

When comparing the IR spectrum in Figure 2A of the samples containing EO with the agar sample, the appearance of characteristic absorption bands for the EO can be observed. Notably, the peak around 1600-1700 cm⁻¹ represents the C = O stretching vibrations,³⁰ characteristic of carbonyl compounds in the EO, such as aldehydes or esters. The absorption band around 1500-1600 cm⁻¹ is related to the C = C vibrations in aromatic rings, which is a characteristic of compounds present in the EO extracted from C. bejolghota leaves. The differences in the IR spectrum between the samples (especially Agar/EO200) and the pure agar sample confirm that the EO has been successfully integrated into the gel structure.

Figure 2.

(A) SEM of agar and 3 samples. (B) IR spectrum of 3 samples and agar. (C) The releasing ability of 3 samples with different oil concentrations in the macroporous gel.

Chacterizations of Macroporous gel

Figure 2B presents SEM images showing the porous structure of agar-based gel and samples containing EO. The Agar sample exhibits very small and uneven pores, indicating that pure agar tends to form a network with fewer pores. However, in the samples containing EO, all three samples demonstrate the formation of larger and more uniform pores compared to the agar sample. The average pore size for these samples is estimated to be in the range of 1-2 µm. Notably, the pore size in Agar/EO200 is the largest, indicating that the addition of EO combined with the freeze-thaw process effectively created a porous network. Compared to study of Podhorská et al reported that gels with pore sizes ranging from 6 µm to 100 µm are suitable for applications such as tissue engineering and drug delivery,³¹ where larger pore sizes are beneficial for cell migration and nutrient diffusion.³² Additionally, a study by Sharma et al showed that gels created from polymer with pore sizes around under 10 µm provide a high drug release in drug delivery applications.³³ Another study of Saqib et al, using other method to carrying natural bioactive compound, spherical rod shape structure ranging from 20 to 30 nm shown effectively inhibition of microbial growth on peach surface and reduced weight loss.^34,35 Therefore, our microporous gel is suitable for applications requiring absorption or controlled chemical release.

As shown in Figure 2C, it illustrates the chemical releasing percentages of oil, and 3 samples during 6 h. The oil shows remained chemical release, consistently nearly 95%. For all three samples exhibit a significant initial chemical release within the first hour, with Agar/EO200 reaching about 30%, Agar/EO100 about 20%, and Agar/EO200 around 15%. After that, Agar/EO200 continues to release chemicals at the highest rate and significant different with other samples. These findings indicate that Agar/EO200 is the most suitable for applications requiring prolonged and efficient chemical release.

Antibacterial and Anti-Inflammatory Activities of Macroporous Gel

Table 3 shows the antibacterial activity of three samples compared to the positive control (ampicillin 0.25 mg/mL), a negative control (sterile RO water), and EO against three bacterial strains: E. coli, S. aureus, and B. cereus. Among the tested samples, Agar/EO200 exhibits the highest antibacterial activity, while Agar/EO50 and Agar/EO100 display moderate antibacterial activity, with inhibition zones around 3 mm for each bacterial strain. This difference is due to the higher concentration of EO in the gel of Agar/EO200 compared to the other two samples. When compared to the positive control, the antibacterial activity is similar, indicating that the gel has good antibacterial properties. This efficacy of C. bejolghota oil is possibly attributed to its diverse content of bioactive compounds, such as 1,8-cineole and γ-terpineol which are known for their strong antibacterial and fungicidal activities.^36–38 Research by Mahboubi and Kazempour suggests that the overall antibacterial activity of EOs is greater than that of their individual major components alone.³⁹

Table 3.

Antibacterial Activity of the Macroporous Gel.

The anti-inflammatory activity of a macroporous gel, as measured by the percentage of nitric oxide (NO) inhibition, for three samples at 3 concentrations, alongside a negative control and a positive control (cardamonin). As shown on the Table 4, the cardamonin at 3.0 µmol/L, exhibits a strong anti-inflammatory response with 83.93% ± 0.76 NO inhibition. Among the tested samples, with the increase in oil concentration, Agar/EO200 demonstrates the highest NO inhibition at 200 µmol/L with 86.01% ± 0.43, indicating significant anti-inflammatory properties. Agar/EO100 also shows considerable activity, especially at 71.07% ± 0.29. In comparison to previous studies, the NO inhibition achieved by Agar/EO200 is on par with other natural anti-inflammatory agents. For instance, a study by Chuysinuan et al reported NO inhibition of around 52% in a sample containing turmeric extract, a well-known anti-inflammatory compound, compare to the control.⁴⁰

Table 4.

Anti-inflammatory Activity of the Macroporous Gel.

Sample name	Concentration (µmol/L)	NO Inhibition (%)	IC50 (µg/mL)
Negative Control (distilled water)	–	100.0 ± 1.3
Positive control (Cardamonin)	3.0	83.93 ± 0.76
EO	100	61.13 ± 0.12
Agar/EO 50	50	57.03 ± 0.81
Agar/EO 100	100	71.07 ± 0.29	74.85
Agar/EO 200	200	86.01 ± 0.43

This study evaluated the antibacterial and anti-inflammatory properties of the gel combined with essential oil (EO). However, the results indicated that the anti-inflammatory activity decreased when EO was incorporated into the Agar gel, as reflected in the IC50 concentrations of EO and Agar/EO. This initial investigation explored the integration of EO into 3D-printed porous gels. While the observed anti-inflammatory activity was somewhat reduced, the primary objective of the formulation was not solely to enhance this specific activity but to address practical challenges associated with the volatility of essential oils. By incorporating EO into the gel matrix, the formulation reduced the evaporation rate and provided a controlled release mechanism, which is particularly beneficial for applications such as food preservation, where the gel can be sprayed onto surfaces to enhance antibacterial effectiveness over time. Although this study did not provide comprehensive data on volatility parameters or potential challenges in large-scale production and application, further research is underway to optimize the formulation and evaluate its performance in relevant scenarios. The findings from these ongoing studies will be published in subsequent works, paving the way for broader applications of EO-integrated porous gels.

Conclusion

The study demonstrated that the macroporous gel containing C. bejolghota EO exhibits significant antibacterial activity, particularly against S. aureus and E. coli. The gel samples showed inhibition zones radius of 8.7 ± 0.94 mm for S. aureus and 6.3 ± 0.26 mm for E. coli, indicating robust antibacterial properties. Compared to the positive control, the macroporous gel's performance is highly promising, especially given the natural origin of the extract. The enhanced functionality of the macroporous gel, including its high porosity and effective antibacterial action. The gel's ability to inhibit bacterial growth can significantly reduce infection rates. The promising results from this study open avenues for further research and development, aiming to harness the full potential of macroporous gels in various biomedical applications.

Footnotes

Acknowledgments

We would like to express our gratitude to the Belarusian Republican Foundation for Fundamental Research and Vietnam Academy of Science and Technology for the financial support.

Author Contributions

Conceptualization: D.T.N., U.T.P. and T.Q.T.; methodology: D.T.N. and U.T.P.; resources: D.T.N. and T.Q.T.; formal analysis: U.T.P., D.T.N. and H.D.T.; data curation: D.T.N., U.T.P. and B.T.H.; validation: N.H.L., T.Q.T. and D.T.N. and U.T.P.; writing—original draft preparation: D.T.N. and U.T.P.; writing—review and editing: D.T.N.P. and D.T.N.; funding acquisition: N.N.T., T.Q.T. and D.T.N.; supervision: X.M.N., T.P.P.L. and D.T.N.; investigation: D.T.N.,; project administration: D.T.N. All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethical Approval

Ethical Approval is not applicable for this article.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by Belarusian Republican Foundation for Fundamental Research (grant no. X22V-006) and Vietnam Academy of Science and Technology (grant no. QTBY01.03/22-23). Grant number: Belarusian Republican Foundation for Fundamental Research (grant no. X22V-006) and Vietnam Academy of Science and Technology (grant no. QTBY01.03/22-23).

ORCID iD

Dung Thuy Nguyen Pham

Statement of Human and Animal Rights

This article does not contain any studies with human or animal participants.

Informed Consent Statement

There are no human subjects in this article and informed consent is not applicable.

Trial Registration Number/Date

Not applicable.

Institutional Review Board Statement

Not applicable.

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