1 Introduction

Drug delivery vehicles have gone much attention over the last few decades. Providing a controlled and localized release of therapeutics within the body are key goals for increasing effectiveness and reducing the dangers of potential side effects [1, 2]. In the meantime, porous Si has been particularly investigated for applications in biological sensors [3, 4] and biomedical devices [5]. The in vivo use of porous Si was first elevated by Canham et al., who proved its resorbability and biocompatibility in the mid1990s [6, 7]. Subsequently, porous SiO2 carrier carriers have been employed to demonstrate in vitro release of the steroid dexamethasone [8], ibuprofen [9], platina [10], doxorubicin [11], and other drugs [12]. In recent years, mesoporous silica (MS) materials such as MCM-41 have been well expanded as effective drug storage carriers in drug delivery systems (DDS). Mesoporous materials have attracted much attention for their excellent properties such as high surface area (>1000 m2/g), tunable and uniform pore size, ease of functionalization, low toxicity, biodegradability, and relatively large pore volume (~1 cm3/g). Moreover production of these materials is relatively simple, inexpensive, and easy controllable [13]. In addition, MS has two functional surfaces, an internal surface and an external surface. This specifications allows the selectively functionalization of surfaces of MS with various sections [14]. The silanol groups in surfaces of MS can be modified with different organic compounds. This process can be increased desirable surface-drug interactions. It is clear which, desirable interactions, can increase loading capacity for the drug molecules and decreased releasing rate of the drug from the MS carriers [15, 16]. Surface modification of MS with organic groups can be performed by two methods, grafting and the co-condensation [17].

Vallet-Regi et al. [18] studied the amine modified MCM-41 materials as Ibuprofen carrier.They observed the decrement of drug release, because the ionic interactions between amine groups and carboxylic groups of drug, and increment of loading drug into SM, because of better adsorption of anionic drugs on modified MCM-41 material. Similarly, studies of the ibuprofen release from modified MCM-41 were published by other researchers [9, 19]. KIT-6 as a MS has pores diameter more than MCM-41. KIT-6 and modified KIT-6 have been used extensively in many interesting applications [20,21,22,23,24,25]. However, there is not much consideration to apply of KIT-6 in DDS versus MCM-41. In 2016, Ayad et al. [13] reported a new application of KIT-6 and KIT-6-NH2 for controlled drug delivery of analgesic drugs.

Resveratrol (RSV) belongs to the large group of biologically active materials found in plants and it is an insoluble drug. It exhibits pleiotropic health beneficial effects [26, 27]. The cancer chemopreventive effects of RSV were recognized in 1997 [28]. In spite of the remedial influence of RSV, its pharmacokinetic properties are not desirable since RSV has poor bioavailability. Prevail over this challenge, DDSs have been expanded to protect and stabilize RSV and to improve its bioavailability. There are various articles about encapsulation of RSV in nano and microformulations [29]. RSV is found in nature as both trans (Scheme 1a) and cis (Scheme 1b) isomers, although the trans-isomer is shown to be the most abundant and biological activity [30].

Scheme 1
scheme 1

Chemical structures of resveratrol isomers. a trans-form and b cis-form

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In our previous work [31], influence of pH and amino group in MCM-41 as a DDS was investigated for the anticancer drug artesunate. In this research, efficacy of pore size and surface area in drug release is compared with two mesoporous (MCM-41 and KIT-6) carriers. In addition to, amine functionalized form of them were used as their application in DDS for the anticancer drug RSV. Mesoporous were used for encapsulation of RSV as a guest in the void space of the carrier mesoporous porosity. These new DDS were characterized by different methods (FTIR, BET, SEM, and XRD). Then the loading capacity and release of RSV as anticancer drug model were studied by TG and UV–visible spectroscopy. The release kinetics of RSV drug from carriers was investigated by applying first order, Higuchi, and Korsmeyer–Peppas release kinetic. Finally, the effect of mesoporous and RSV@mesoporous DDS was evaluated on MCF-7 human breast cancer cell viability.

2 Experimental section

2.1 Materials

3-Aminopropyl triethoxysilane (APTES, Sigma-Aldrich), hydrochloric acid (merck), Triblock poly (ethylene oxide)-b-poly(propyleneoxide)-b-poly(ethyleneoxide) copolymer Pluronic P-123 (Sigma-Aldrich), tetraethoxysilane (TEOS, Sigma-Aldrich), hexadecyltrimethylammonium bromide (CTAB, Sigma-Aldrich), n-butanol (merck), NaOH (merck), and RSV (Sigma-Aldrich) were used as received. All raw chemicals were purchased and applied without any further purification.

2.2 Synthesis of MCM-41

The MCM-41 was synthesized based on our previous article [31].

2.3 Synthesis of KIT- 6

KIT-6 was synthesized based on sol–gel method in accordance with the previous report [32]. Commonly, hydrochloric acid (1.65 g, 35%) was added to 1 g of Pluronic® P123 dissolved in 36 mL distilled water and stirred at 35 °C for 4 h. Then, the mixture was added in n-butanol (1.23 g) and blended at 35 °C for 1 h until a clear solution was obtained. Afterward, 2.25 g TEOS was added drop wise with stirring into the homogenous clear solution and go on stirring at 35 °C for 24 h. After that, the solution was heated in autoclave at 100 °C for 24 h. Ultimately; KIT-6 was successfully obtained. The sample was then filtered and washed with distilled water, and finally dried at 100 °C for 12 h in oven. The dried product was heated with air to 550 °C for 6 h.

2.4 Postsynthesis grafting of the APTES on mesoporous

The post-synthesis grafting procedure involved mixing 1 g of calcined mesoporous and 1.6 g APTES in 50 ml toluene at 60 °C for 1 h. The obtained sample was filtered, washed with dichloromethane and dried in an oven under air atmosphere at 80 °C for 5 h [33]. The formation mechanism of mesopore-NH2 was proposed according to Scheme 2. The amine functionalized forms of carriers are abbreviated as MCM-41-NH2 and KIT-6-NH2.

Scheme 2
scheme 2

The formation mechanism of mesopore-NH2

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2.5 Drug loading and release

RSV was loaded into silica carriers (MCM-41, KIT-6) and their functionalized forms (MCM-41-NH2, KIT-6-NH2) in the following two methods (simple mixing and high pressure methods). In simple mixing system, the all carriers were mixed with the dissolved RSV in ethanol and then were stirred magnetically for 24 h at room temperature. Prepared sample was left for 1 h then was dried for 12 h at 60 °C. In the loading under high pressure system, RSV and mesoporous were mixed at a weight ratio of 1:5 and put into a high-pressure adsorption equipment at 30 MPa and 298 K for a period over 24 h. Subsequently being washed with distilled water to remove the unentrapped drug, the powders were dried in a vacuum oven at 65 °C for 6 h (Scheme 3). The prepared samples with simple mixing method are called RSV@MCM-41/SM, RSV@MCM-41-NH2/SM, RSV@KIT-6/SM, and RSV@KIT-6-NH2/SM. The synthesized samples with high pressure method are abbreviated RSV@MCM-41/HP, RSV@MCM-41-NH2/HP, RSV@KIT-6/HP, and RSV@KIT-6-NH2/HP. The amount drug loading was evaluated by TGA. Previous article was used for studying release profiles [34].

Scheme 3
scheme 3

Schematic representation summarizes synthesis of RSV@MCM-41-NH2 or RSV@KIT-6-NH2 based on a favorable hydrogen bonding interaction by high pressure method

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2.6 Cell culture conditions and viability

Human breast adenocarcinoma-derived cell line MCF-7 was benevolently supplied by IBRC (Iranian Biological Resource Center Institute Pasteur). Cell culture conditions and viability was performed based on our previous article [31].

2.7 Characterization

The MCM-41 was adverted using powder X-ray diffraction (pXRD) (a Philips PW1710 diffractometer with Cu Kα and a nickel filter) and mesostructural ordering of the KIT-6 was carefully investigated by low-angle X-ray powder diffraction (a Panalytical PW3050 diffractometer with Cu Kα A). The broad-range pattern (2θ = 2 to 10 for MCM-41 and 2θ = 0.71 to 8 for KIT-6 with a 0.02 step size, 1 s/step) was collected at room temperature. Surface areas and pore volumes of the porous materials were measured using nitrogen adsorption. Nearly 100 mg of mesopore was dried overnight at 120 °C in vacuum. BET surface area and pore size (BJH method) were determined by N2 adsorption using a Sorptometer Kelvin 1042. Thermogravimetric analysis (TGA) was conducted using a TGA/DSC Instruments LINSIES STP PT-1000 with a heating rate of 5 °C/min under air atmosphere. The APTES and RSV loading were calculated from the weight loss measured by TGA assuming that all of the ethoxy groups were hydrolyzed and/or bonded to the silica surface and decomposed loading RSV. FT-IR spectra were recorded by the Nicolet FT-IR and spectrometer, and the samples were pressed into disks by blending them in the ratio of 1:10 with KBr. The spectra were recorded in the range of 400−4000 cm−1. The electronic UV−visible absorption spectra of RSV and residual solutions were recorded in the range 200−700 nm in a Shimadzu UV/2501PC spectrophotometer, using quartz cells at room temperature. Morphology was estimated using scanning electron microscopy (SEM). Images were taken with a LEO 1430VP in high vacuum mode. To avoid surface charging, all samples were gold coated at room temperature under vacuum prior to analysis, using a Fisons Instruments SC502 sputter coater.

3 Results and discussion

3.1 Characterization of DDS

The anticancer drug RSV was loaded in MCM-41, KIT-6, and their functionalized forms were used in DDSs. In DDSs, drug diffuse into the space available of the mesoporous framework and the starting carriers are not cytotoxic to the MCF-7 cell line. Therefore, initial studies with KIT-6, MCM-41, and modified mesoporous were performed. These structures indicated to be nontoxic to the cells. The loading of RSV into mesoporous and modified mesoporous were assessed by gravimetric analysis. Table 1 appears the loading obtained for all prepared DDS. The high pressure loading method and functionality improve the amount of RSV loading due to elimination solvent and stronger interaction between RSV and carrier, respectively. Then synthesized samples by high pressure method were used for DDS. The highest RSV loading was observed for MCM-41-NH2 in high pressure loading method. Because the percentage of drug loading in carriers depends on surface area and functionalized groups of carriers more than pore size patently.

Table 1 Loading of RSV in the DDSs
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3.1.1 TGA analysis

TGA of samples by the high pressure method are shown in Fig. 1. The two weight losses around 300 °C (the beginning melting) and 500 °C (the decomposition) were observed for thermogram of pure RSV [35]. All the samples (carriers and modified carriers) showed an initial weight loss at about 100–150 °C due to the physically adsorbed water molecules. In addition, there is no significant weight loss due to disintegration of KIT-6 or MCM-41 which implied that the pure mesoporous carriers are thermally stable. The thermal decomposition of the modified carriers occurred in the interval of temperatures between 150 and 400 °C as a result of the decomposition of -NH2 groups in carriers.

Fig. 1
figure 1

TGA of the samples

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When RSV drug was loaded in KIT-6 and MCM-41 materials an expanded range of temperature was demonstrated for the decomposition of the drug (Table 1). In case of APTES functionalized samples, the loss of physisorbed water and decomposition of RSV was observed around 250 °C and 500 °C, respectively.

3.1.2 XRD study of samples

The XRD patterns of mesoporous carriers and DDS are demonstrated in Fig. 2. The XRD pattern of MCM-41 was in accordance with other article (Fig. 2a) [36]. The same study was also fulfilled in the low-angle X-ray diffraction patterns (low-angle XRD) for the KIT-6 (Fig. 2b). KIT-6 showed a well-determined diffraction peak at 2θ = 0.9° (211), indicating the formation of a great structural ordering with a symmetry of the body-centered cubic (bcc) space group Ia3d [13]. The diffraction patterns for the amine functionalized mesoporous (KIT-6-NH2 and MCM-41-NH2) indicated reduce intensity that can be attributed to drop off the long-range ordering of the mesoporous structure. However, the decreased intensity of the (211 for KIT-6) and (100 for MCM-41) diffraction peaks was observed after loading of RSV drug in amine functionalized mesoporous but their mesoporous structure was kept. In other words, modification of external and inner surfaces of pore walls with Pr-NH2 groups is proved by the low intensity of the (211 and 100) diffraction peaks, while the structure of carrier remained unaltered after modification and RSV loading [13].

Fig. 2
figure 2

XRD patterns of a MCM-41 and b KIT-6 samples in the low angle

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3.1.3 BET results

The nitrogen adsorption–desorption measurements for all carriers and RSV loaded mesoporous samples are observed in Table 2. The pore volume of carriers decreased after functionalization and loading of RSV. Thus, RSV drug was incorporated into carriers’ pores without influencing the mesostructure [37]. Nitrogen adsorption–desorption isotherms for MCM-41 and KIT-6 carriers and RSV loading in carriers with and without amine functionalized are shown in Fig. 3. All the samples followed type IV isotherms. The nitrogen absorption–desorption isotherms for the MCM-41 and RSV loading in MCM-41 carriers (Fig. 3a) showed a steep increase in the nitrogen uptake around P/P0 ~ 0.2, which can be related to capillary condensation in cylindrical pores of MCM-41 by hydrothermal method [38]. The large hysteresis loops for KIT-6 and modified KIT-6 samples indicated that the KIT-6 samples have an unvarying pore texture with large channel-like mesoporous.

Table 2 Physicochemical Properties of the host materials before and after RSV Loading
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Fig. 3
figure 3

Nitrogen adsorption–desorption isotherms of a MCM-41 and b KIT-6 samples

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3.1.4 SEM images

The morphology of the carriers before and after RSV loading was studied by SEM images (Fig. 4). The uniform RSV drug was dispersed on the surface MCM-41 and MCM-41-NH2 carriers. The dispersion of RSV drug was not observed on the surface of KIT-6 and KIT-6-NH2 carriers. The SEM images showed that no changes occurred in the morphology and structure of carriers upon the incorporation of the RSV. The BET results indicated that RSV drug was encapsulated in the pore of carriers, but SEM images showed that more of RSV drug was located on the surface of MCM-41 and MCM-41-NH2 carriers and the results were versa in case of KIT-6 carriers. Probably, the more RSV drug located into the pore of KIT-6 because the pore size diameter of KIT-6 is bigger than MCM-41 (Table 2). The reports have demonstrated that the amino and silanol groups can be observed in both, surface and channels of mesoporous materials [39]. Due to the presence of these silanol groups on the surface of MS, RSV also can be found on the surface.

Fig. 4
figure 4

SEM images of carriers before and after RSV loading

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3.1.5 FT-IR study

The presence of the RSV and its interaction with mesoporous carriers were probed by fourier transformed infrared spectroscopy (FT-IR) (Fig. 5). The FT-IR spectrum of MCM-41 carrier showed bands at 1077, 807, and 610 cm−1 which could be attributed to Si–O–Si bending and stretching vibrations. The band of OH-group in the parent MCM-41 observed at 3439 cm−1 [34]. MCM-41-NH2 carrier indicated Si–C and C–N stretching vibrations at 695 and 1511 cm−1. FT-IR spectrum of the KIT-6 also shows a number of characteristic bands in Fig. 5. The band appeared at 3435 cm−1 was assigned to the stretching vibration of hydrogen bonded silanol group. The appeared band at 1630 cm−1 was attributed to the O–H bending vibration of physisorbed water molecules. Two predictable bands at 1084 cm−1 and 820 cm−1 were related to the anti-symmetric and symmetric stretching vibration of Si–O–Si [40]. Upon functionalization, the vibration of NH2 groups was observed at 3460 cm−1 which extended along the O–H stretching vibration [41]. However, the band located at 1560 cm−1 clearly indicated the presence of N–H (in APTES) bending vibration [41]. To explore the successful loading of RSV drugs into the carriers, FT-IR measurements were conducted, as well. The FT-IR spectrum of RSV shows three characteristic strong bands at 1606, 1585, and 1384 cm−1, belonging to double bond C─C stretching of aromatic and olefinic groups, and ring C–C stretching, respectively. The bands at 1511, 1443, and 1324 cm−1 can be agreed with in plan and out of plane C–H bending, respectively [42]. After encapsulation of RSV drug into mesoporous frameworks, a slight shift and intensity reduce were observed for bands of vinylidene groups (1324 cm−1). These spectra feature due to interaction of RSV C═C with the carriers.

Fig. 5
figure 5

The infrared spectra of all samples

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3.2 RSV release from MS carriers

To demonstrate the effect of the amino-function group, surface area and pore size in release behavior of drug, MCM-41, KIT-6, and functionalized MS as carriers were used to encapsulate RSV drug and studied the release property of drug by UV–vis spectroscopic measurements. The range of pH breast cancer cells is between 7 and 7.4 [43, 44]. So, the drug release behaviors of RSV from the mesoporous carriers were considered in phosphate buffer as a function of pH (7 and 7.4) at room temperature. The pH-triggered release of RSV drug was studied using UV–vis spectroscopy at 310 nm. The release property depends on the nature of interactions between the RSV and carriers. Figure 6a shows the release percentage after 24 h in different media for RSV@MCM-41, RSV@KIT-6, RSV@MCM-41-NH2, and RSV @KIT-6-NH2 samples. The release percent of RSV drug in functionalized carriers in both pH was less than unmodified mesoporous, due to strength interaction between hydroxyl groups of RSV drug and –NH2 group functionalized mesoporous. The slower release rate of MCM-41 compared with KIT-6 can be also explained by the lowering the pore diameter of MCM-41. The decreases of pore size in modified carriers compared to unfunctionalized mesoporous are in agreement with BET results. The results indicated that the drug release process was mainly relied on the groups functionalization (such as –NH2) rather than porosity [45].

Fig. 6
figure 6

The release percentage after 24 h in different media for RSV@unfunctionlized mesopores and RSV@mesopores-NH2 samples a and comprasion of release percentage between encapsulated and nonencapsulated RSV b

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Figure 6b depicts comprasion of release percentage between encapsulated and nonencapsulated RSV. In pH 7 about 40.3% and in pH 7.4, 40.9% of RSV molecules were released from MCM-41-NH2 in the first 6 h. At the similar time, the release percent of RSV was 46.3% and 50.3%, in pH = 7 and 7.4 for KIT-6-NH2, respectively. After 14 h, the release percent of RSV was measured 47.4% and 51.8%, for MCM-41-NH2 and 53.9% and 62.7% for KIT-6-NH2 in pH = 7 and 7.4, respectively. On the basis of the obtained experimental results, the release percent was increased by decrement of the H+ concentration. Because hydrogen bond interaction between RSV drug and –NH2 group in carriers become weak, then further dissociation of RSV occurred leading to an increase in release percent. As a consequence, loading of amine group in carriers, pH environment and pore size of carriers can affect the release of the RSV.

In most experiments RSV has been applied in a free form dissolved in various organic solvents (i.e., DMSO, acetone, and ethanol) that are not suitable for drug delivery and poor water solubility is disadvantageous property that justifies its encapsulation in carriers. The release profiles of RSV@ carriers and nonencapsulated RSV are presented in Fig. 6b. The release percentage was measured for 6, 14, and 20 h in pH = 7 and 7.4.The results indicates that the selected carriers and loading RSV substantially facilitate dissolution of RSV.

Drug release from porous media can act according to several different models which we explained them in our previous work [31].The release kinetic models such as first-order, Higuchi, and Korsmeyer–Peppas equations was used for determination of RSV drug release kinetic process. The linear plots of release kinetics are indicated for RSV drug released from RSV@MCM-41, RSV@MCM-41-NH2 in Fig. 7 and are observed for RSV@KIT-6 and RSV@KIT-6-NH2 samples in Fig. 8. Table 3 demonstrated the parameters of all release kinetic models of RSV drug from mesoporous materials. It was resulted that the release of RSV from carriers follows a first-order kinetic (Figs. 7a, b and 8a, b). For the sake of comparison, the amine group in carriers leading to increment of first-order rate constant, k1. Because the amine group increased pore blocking carriers due to interaction with RSV drug. The calculated values of n from Korsmeyer–Peppas equation indicated the release mechanism pursues the anomalous (non-fickian) transport mechanism (Table 3) (Figs. 7c and 8c) [13, 46]. Therefore, the initial release can be attributed to depleting of free drug molecules from the carriers pore or from carriers surface, then, as the solvent exits from the carrier pores, RSV drug dissolve slowly into the release media. All results demonstrated that, high surface area and functionalized groups led to the increment loading capability of drug molecules in carriers. On the other hand, the release rate of drug depends on pore size and functionalized groups. Thus, chemical functionalization can be an important role in increment of drug loading and release rate.

Fig. 7
figure 7

Release kinetic models of RSV from a RSV@MCM-41 and b RSV@MCM-41-NH2 in different pH ranges (PH 7 and 7.4): a First order, b Higuchi, and c Korsmeyer–Peppas kinetics

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Fig. 8
figure 8

Release kinetic models of RSV from a RSV@KIT-6 and b RSV@KIT-6-NH2 in different pH ranges (PH 7 and 7.4): a First order, b Higuchi, and c Korsmeyer–Peppas kinetics

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Table 3 Release kinetic parameters of RSV drug
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3.3 Drug bioactivity studies

The modified and unmodified carriers demonstrated small or no effect on MCF-7 breast cancer cell line. In fact the used carriers were nontoxic to the cells. This process is one of the important parameters of acceptable DDS. The effect of all carriers on the viability of MCF-7 cells is shown in Fig. 9a.

Fig. 9
figure 9

The effect of hosts on MCF-7 breast cancer cell viability with the different concentrations of mesopores hosts for 24 h a. The effect of RSV@carriers and nonencapsulated RSV on MCF-7 breast cancer cell viability for 24 h b

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The different amounts of synthesized DDS and carriers (0.05, 0.1, and 0.2 mg/ml) was assayed on MCF-7 cell viability for 24 h (Fig. 9b). With increasing concentrations of RSV drug in the carriers, was observed an evident reduction in cell viability, from 60 to 51% for KIT-6, 67 to 52% for MCM-41, 73 to 62% for KIT-6-NH2 and 80 to 69% for MCM-41-NH2. The RSV loaded MCM-41 or KIT-6 carriers demonstrated cytotoxic effect clearer than of RSV drug incorporated in the functionalized carriers. However, the incorporation of drugs in porous carriers can improve their activity, stability and selectivity, but decrease of drug dosage for inhibition of cell viability compared to nonencapsulated drugs is one of the advantages of loading of drugs (Fig. 9b). 0.2 mg/mL concentration of RSV drug was necessary for a 13% of inhibition of cell viability. In contrast to, with the encapsulated drug in mesoporous carrier for the more magnitude of inhibition (20%), requisite dosage of RSV decrease to 0.05 mg/mL for RSV@MCM-41-NH2 DDS (Fig. 9b), therefore there is an increase in efficiency of the drug in DDSs. MCM-41 and KIT-6 carriers were more effective than their functionalized forms (MCM-41-NH2 and KIT-6-NH2) due to the more open structure of mesopores and weaker interaction drug-carriers which RSV drug could freely diffuse to the outside of the structure toward the cells. KIT-6-NH2 was more effective than MCM-41-NH2 carrier since pore size of KIT-6-NH2 is bigger than MCM-41-NH2, but loading of RSV drug in MCM-41-NH2 carrier was more than KIT-6-NH2 carrier (due to high surface area in MCM-41). As a consequence, by incorporating RSV into MCM-41 and KIT-6 carriers, the efficiency of RSV drug significantly was increased, which could be related to RSV solubility. Thus, the pore diameters and surface area with the subsequent addition of organic function groups greatly enhance the loading and release of drug molecules and hence its kinetics. Thus, we believe that the MS DDSs allow the slow release of RSV, increasing the bioavailability of the insoluble drug, and thus explaining this increase in potency. Our method indeed could realize high loading capacity, reduction of dosage, increasing of solubility and slow release rate, which represents a promising carrier for future DDS.

4 Conclusions

In conclusion, we present synthesis of MS KIT-6 and MCM-41 by sol–gel and hydrothermal methods, respectively. The MS materials were fictionalized by –NH2 groups. The synthesized mesoporous materials and their modified forms were used as carrier materials and characterized to evaluate their ability to encapsulate and release the experimental anticancer drug RSV. RSV was incorporated in carriers by two methods, mixing and high pressure methods. The loading of drug RSV in carriers by high pressure method was more than mixing method. Modified carriers with high surface area such as MCM-41-NH2 indicated high loading of RSV drug. The release of drug depends on pore size of carriers and functional groups. The release of RSV drug in KIT-6-NH2 due to big pore size was more than MCM-41-NH2 carriers. Meanwhile, modified carriers (MCM-41-NH2 and KIT-6-NH2) demonstrated lower release with respect to unmodified carriers. The effect of the MS carriers and RSV @mesoporous DDS on the MCF-7 breast cancer cell line viability was assessed. Mesoporous carriers alone appeared no toxicity to MCF-7 cancer cells. Importantly, RSV@mesoporous materials led to more inhibition of cell viability when compared to the nonencapsulated form. The inhibition of cell viability of RSV@KIT-6-NH2 is more than RSV@MCM-41-NH2 due to drug loading in carriers depends on surface area and functionalized groups of carriers more than pore size. As a consequence, RSV@MCM-41-NH2 as a DDS caused the slow release of RSV, growing the bioavailability of the drug, and thus explaining this increase in potency. These results demonstrate the potential of the MS materials for drug loading, and delivery to cancer cells.

5 Disclaimer

The article is original and it has been written by the stated authors who are all aware of its content and approve its submission. The manuscript has not been published previously and it is not under consideration for publication elsewhere. If our manuscript accepted, the article will not be published elsewhere in the same form, in any language, without the written consent of the publisher.