PROCESS FOR OBTAINING A HYBRID SYSTEM, HYBRID SYSTEM AND ITS USE

Abstract

The present invention provides a process for producing a hybrid system containing a biocompatible polymer hydrogel and mesoporous silica nanoparticles incorporating drugs, as well as the hybrid system and use thereof for anti-tumour treatment. More specifically, the hybrid system of the present invention comprises doxorubicin (DOX) and / or sildenafil as drugs incorporated in the pores of the nanoparticles, with the aim of producing novel material for anti-tumour treatment, especially for treating prostate cancer.

Description

1 / 23 PROCESS FOR OBTAINING A HYBRID SYSTEM, HYBRID SYSTEM AND ITS USE Field of invention: [1] The invention described herein falls within the field of nanotechnology, particularly as applied to the medical field, and describes the process of obtaining a hybrid system based on biocompatible polymer hydrogels and mesoporous silica nanoparticles incorporated with antitumor drugs. [2] Additionally, the invention describes said hybrid system and its use in antitumor treatment, in particular in the treatment of prostate cancer. Fundamentals of the invention: [3] The enormous potential of nanotechnology has generated competitiveness among countries around the world, boosting the search for and production of new nanomaterials in a wide variety of areas, including medicine, with regard to nanoscale drugs. [4] Nanotechnology encompasses aspects such as the design, characterization, production and application of structures by controlling shape and size on a nanometric scale. The so-called nanomaterials refer to those whose size varies on the nanometric scale and which exhibit properties and functions distinct from materials of the same composition with larger dimensions. [5] These properties are the result of both quantum effects, which come to dominate the behavior of matter at very small dimensions (thus modifying optical, electrical and magnetic properties), and the high surface area to volume ratio of nanoparticles. In addition to the high surface area Petition 870260063790, dated 06 / 29 / 2026, page 5 / 61 2 / 23 Surface nanomaterials exhibit high surface reactivity due to their lower coordination number and greater exposure to reactive species. [6] The use of nanomaterials for sustained drug release presents numerous advantages over the use of free drugs. These systems improve the solubility of certain molecules and prevent premature drug degradation. Furthermore, as they can be target-specific, they increase the concentration of the drug in the tissues of interest, making it necessary to use lower doses. [7] An ideal hypothetical nanocarrier must meet the following criteria: be composed of biocompatible and biodegradable material, have a high drug delivery capacity, possess a site-specific release mechanism, not release the drug prematurely and, finally, possess a controlled release mechanism to achieve an effective dose at the target site. [8] Porous silica nanoparticles have excellent prospects for use as drug delivery systems and have demonstrated high biocompatibility and safety profile, encouraging investigations leading to clinical research. These particles have a high surface area and large pore volume, and can carry several drugs simultaneously, even those with distinct physicochemical properties. Additionally, they are easily functionalized and convenient for carrying drugs and biomolecules. [9] An efficient way to synthesize porous silica nanoparticles is based on a modification of the Stober method, a sol-gel method in which silicon alkoxides are Petition 870260063790, dated 06 / 29 / 2026, page 6 / 61 3 / 23 are used as precursors and, through hydrolysis and condensation reactions in an ammoniacal medium, a new sol phase is formed in which the colloidal particles are condensed. The reaction medium also includes ethanol as a homogenizing agent and a cationic surfactant (cetyltrimethylammonium halides) that generates the pores.

[10] Through adaptations to the Stober method, it is possible to produce porous particles with high colloidal stability, different sizes, as well as high surface area value.

[11] In addition to enabling the release of more than one drug simultaneously, porous silica nanoparticles have low toxicity, differentiating them from most inorganic nanomaterials, which gives them a versatile range of biomedical applications.

[12] Although good results are being obtained in investigations of these nanomaterials for use in antitumor treatment, more studies are needed to determine the behavior of these structures in blood and other biological environments.

[13] Since the biological activity of nanomaterials is directly related to their morphology (particle size and shape, pore size, as well as surface properties), it is possible to modify these parameters in order to obtain more biocompatible nanostructures.

[14] In this context, Pluronic F-127 is a block copolymer consisting of polyethylene oxide (PEO) and polypropylene oxide (PPO) monomers arranged in a PEO-PPO-PEO triblock structure, which has biocompatible and thermoreversible properties. Petition 870260063790, dated 06 / 29 / 2026, page 7 / 61 4 / 23

[15] Its liquid-gel transition temperature is close to room temperature, which makes it excellent for pharmaceutical formulations aimed at achieving sustained drug release and in situ gelation. Hydrogels represent a promising alternative in sustained drug release, as they are biocompatible and can be administered in a virtually non-invasive manner.

[16] Sustained release can be controlled by means of various stimuli, such as temperature or pH, in addition to the possibility of varying the chemical structure of the polymer chains in order to control the physicochemical properties of the hydrogel, according to the desired application.

[17] Given the potential of nanostructures for sustained drug release, treatments against various types of cancer using these materials have been widely considered and the use of nanotechnology for the development of various chemotherapies has become a valuable therapeutic option.

[18] Among the various types of cancer, prostate cancer has a high probability of incidence, being considered an epithelial disease that frequently extends beyond the normal limits of the organ.

[19] Given the strategic role of chemotherapeutic agents and the difficulty in obtaining new therapies, the association of nanomaterials and drugs already used in this treatment, such as doxorubicin (DOX), stands out.

[20] DOX is a broad-spectrum antitumor antibiotic widely used to treat various cancers, including breast, ovarian, and prostate cancer. The effectiveness of Petition 870260063790, dated 06 / 29 / 2026, page 8 / 61 5 / 23 DOX is limited due to its high toxicity and side effects, which include myelosuppression, alopecia, nausea, vomiting, cardiotoxicity, and resistance after repeated doses.

[21] Furthermore, sildenafil stands out as an alternative to minimize the side effects caused by DOX. Different studies have shown that sildenafil promotes a protective effect against heart failure and ischemia induced by DOX.

[22] In view of the foregoing, the present invention provides a process for obtaining a hybrid system based on biocompatible polymer hydrogels and mesoporous silica nanoparticles incorporated with drugs with antitumor potential, as well as said hybrid system and its use in antitumor treatment.

[23] Specifically, the hybrid system of this invention comprises the drug DOX, associated with sildenafil or not, as drugs incorporated into the pores of the nanoparticles, with the aim of producing a new biocompatible material for the treatment of prostate cancer. State of the art:

[24] The technology described in the present invention relates to the process of obtaining a hybrid system, wherein the hybrid system is composed of a hydrogel of biocompatible polymers and mesoporous silica nanoparticles comprising DOX and / or sildenafil incorporated as well as said hybrid system and its use in antitumor treatment, preferably of prostate cancer.

[25] Several documents available in the state of the art report the use of polymer thermogels Petition 870260063790, dated 06 / 29 / 2026, page 9 / 61 6 / 23 biocompatible materials applied to controlled drug release procedures.

[26] In addition, there are also known documents that describe mesoporous silica nanoparticles containing incorporated antitumor drugs, forming systems applied for cancer treatment.

[27] In US6369037B1, reference is made to a hydrogel composed of dextran-methacrylate as a carrier, the production process of which uses organic solvents. However, the invention described does not use nanoparticles for drug incorporation, as proposed in the present invention.

[28] US6632457B1 document proposes the formation of hydrogel composites for the controlled release of drugs. However, nanoparticles are not part of the invention and surfactants are proposed as phase transfer agents and not as the hydrogel matrix.

[29] Document US20120207795A1 discloses mesoporous silica nanoparticles for carrying therapeutic drugs and includes the use of cationic polymer or copolymer, not covering the use of block copolymers or hydrogel as a matrix as proposed in the present patent application.

[30] US2002076441 document highlights a system of microparticles or nanospheres in a polyester / polyethylene glycol copolymer gel for controlled release of bioactive agents. However, it does not cover the use of monodisperse mesoporous silica nanoparticles.

[31] In US2007269488, silica nanoparticles in nanocomposite hydrogel are described (produced through a polymerization process using agents Petition 870260063790, dated 06 / 29 / 2026, page 10 / 61 7 / 23 crosslinking) for ophthalmic applications. However, the nanoparticles used in the invention do not act as drug carriers and there is no association of drugs with the nanoparticles or with the hydrogel.

[32] The technology proposed in the present invention differs from others in that it refers to silica nanoparticles with a monodisperse profile and identical porosity and surface characteristics, providing colloidal stability, an essential characteristic for anticancer applications.

[33] The biocompatible polymer hydrogel described in the proposed technology, unlike other copolymer gels, provides controlled drug release and biocompatibility of the hybrid system in biological systems.

[34] Considering the above, the controlled release of doxorubicin and / or sildenafil as antitumor drugs in a hybrid system consisting of mesoporous silica nanoparticles and copolymer gels is new and inventive compared to the teachings of the state of the art. Brief description of the invention:

[35] The present invention provides a process for obtaining a hybrid system based on biocompatible polymer hydrogels (block copolymer consisting of polyethylene oxide (PEO) and polypropylene oxide (PPO) monomers arranged in a PEOPPO-PEO triblock structure) and mesoporous silica nanoparticles incorporated with drugs comprising DOX and / or sildenafil with antitumor potential, as well as the hybrid system and its use in antitumor treatment. Petition 870260063790, dated 06 / 29 / 2026, page 11 / 61 8 / 23

[36] More specifically, the hybrid system of this invention comprises mesoporous silica nanoparticles with the drugs DOX and / or sildenafil incorporated into their pores, with the aim of producing a new biocompatible material for the treatment of prostate cancer. Brief description of the figures:

[37] To obtain a full and complete visualization of the object of this invention, the figures to which reference is made are presented, as follows.

[38] Figure 1 graphically represents the thermogram of the sample of mesoporous silica nanoparticles in deionized water.

[39] Figures 2A-C represent TEM images of mesoporous silica nanoparticles.

[40] Figure 3 represents the nitrogen adsorption-desorption isotherm of mesoporous silica nanoparticles.

[41] Figure 4 graphically represents the colloidal stability of mesoporous silica nanoparticles in 0.9% physiological saline (NaCl) solution when in the presence of 0.01%; 0.10%; 0.50%; and 1.00% copolymer.

[42] Figures 5A and 5B graphically represent the aggregation profile of mesoporous silica nanoparticles when in the presence of copolymer percentages of 0.01% to 0.10% and 0.50% to 1.00%, respectively.

[43] Figures 6a, 6b and 6c graphically represent the dissolution profile of the hydrogel with a copolymer concentration of 18% and DOX release when in the absence of nanoparticles and in the presence of 1 mg / mL and 5 mg / mL of mesoporous silica nanoparticles, respectively. Petition 870260063790, dated 06 / 29 / 2026, page 12 / 61 9 / 23 Detailed description of the invention:

[44] The present invention provides a process for obtaining a hybrid system based on biocompatible polymer hydrogels and mesoporous silica nanoparticles incorporated with DOX and / or sildenafil.

[45] The process comprises the following steps: a) Synthesis of mesoporous silica nanoparticles: a1) Dissolving the cationic surfactant in an alkaline solution with a pH between 10 and 12, preferably 11; a2) Homogenizing the solution by sonication for 1 to 30 minutes, preferably 10 minutes; a3) Addition of absolute ethanol to the solution obtained in step a2 and stirring at 60 to 6000 rpm, preferably 300 rpm, for 5 to 30 minutes, preferably 15 minutes; a4) Addition of tetraethoxylysane to the solution obtained in step a3 for chemical reaction for 1 to 3 hours, preferably 2 hours, at a temperature between 30 and 80°C, preferably 60°C; a5) Centrifugation of the solution obtained in step a4 at 500 to 19000 rcf, preferably 18000 rcf, for 15 to 120 minutes, preferably 60 minutes, at temperatures between 4 and 35°C, preferably 4°C; a6) Suspension of the nanoparticles centrifuged in step a5 in ethanol and storage in a refrigerator at temperatures of 1 to 15°C, preferably 4°C; a7) Extraction of cetyltrimethylammonium from the nanoparticles obtained in step a6, by adding absolute ethanol, homogenization in an ultrasonic bath for 5 to 30 minutes, preferably Petition 870260063790, dated 06 / 29 / 2026, page 13 / 61 10 / 23 minutes; and addition of analytical grade hydrochloric acid to the solution, homogenizing in an ultrasonic bath for 5 to 60 minutes, preferably 60 minutes; a8) Centrifugation of the solution obtained in step a7 for 15 to 120 minutes, preferably 60 minutes, with removal of the supernatant, washing with absolute ethanol twice, centrifugation of the solution at 500 to 19000 rcf, preferably 18000 rcf; and obtaining a suspension of mesoporous silica nanoparticles in absolute ethanol; b) Obtaining a biocompatible polymer solution: b1) solubilization of copolymer in physiological saline to obtain a 30% (w / w) solution; b1.1) Addition of physiological saline solution to a bottle, under agitation, until thermal equilibrium is reached, maintaining the temperature between 0 and 35°C, preferably 4°C; b1.2) Addition of the copolymer to the physiological saline obtained in step b1.1 and its dissolution, maintaining the temperature at 0 to 35°C, preferably 4°C; to obtain a biocompatible polymer solution; c) Obtaining the hybrid system: c1) Addition of drug to the biocompatible polymer solution obtained in step b1.2 in order to achieve a concentration between 0.01 mg ml-1 and 10 mg ml-1, preferably 1.25 mg ml-1, under stirring, in a water bath with a temperature varying between 0 and 35°C, preferably 4°C; Petition 870260063790, dated 06 / 29 / 2026, page 14 / 61 11 / 23 c2) addition of sodium chloride to the system obtained in step c1, to obtain a 0.9% saline system; c3) suspension of the mesoporous silica nanoparticles, obtained in step a8, in deionized water; c4) addition of the suspension of mesoporous silica nanoparticles obtained in step c3 to the saline system obtained in step c2, under agitation at 60 to 6000 rpm, preferably 300 rpm, maintaining the temperature at 0 to 35°C, preferably 4°C, for 0 to 72 hours, preferably 48 hours, obtaining the hybrid system; and c5) gelation of the hybrid system, obtained in step c4, at room temperature. - Synthesis of mesoporous silica nanoparticles:

[46] Mesoporous silica nanoparticles are synthesized using the adapted Stober method. In this way, porous nanoparticles with high colloidal stability, defined size, high surface area value and high pore volume value are obtained.

[47] Thus, for the synthesis of nanoparticles, a cationic surfactant with linear alkyl chains, preferably cetyltrimethylammonium bromide, is dissolved in an alkaline solution preferably comprising ammonium hydroxide, at a pH between 10 and 12, preferably 11, and homogenized by sonication for 1 to 30 minutes, preferably 10 minutes.

[48] ​​Absolute ethanol is added to this solution. After 5 to 30 minutes, preferably 15 minutes, under stirring at 60 to 6000 rpm, preferably 300 rpm, tetraethoxysilane is added. The reaction is maintained at 30 to 80°C, Petition 870260063790, dated 06 / 29 / 2026, page 15 / 61 12 / 23 preferably at 60°C, for 1 to 3 hours, preferably 2 hours, under a reflux system, to prevent ethanol evaporation.

[49] After this period has ended, the products are separated by centrifugation at 500 to 19000 rcf, preferably 18000 rcf, for 15 to 120 minutes, preferably 60 minutes, at temperatures of 4 to 35°C, preferably 4°C.

[50] Next, the nanoparticles were suspended in ethanol and stored in the refrigerator at temperatures of 1 to 15°C, preferably 4°C, for subsequent removal of the cetyltrimethylammonium.

[51] To extract cetyltrimethylammonium, absolute ethanol is added to the suspension and homogenized in an ultrasonic bath for 5 to 30 minutes, preferably 5 minutes. Then, analytical grade hydrochloric acid is added, homogenizing in an ultrasonic bath for 5 to 60 minutes, preferably 60 minutes.

[52] Subsequently, centrifuge for 15 to 120 minutes, preferably 60 minutes, removing the supernatant and finally washing with absolute ethanol twice, centrifuging afterwards.

[53] Mesoporous silica nanoparticles are monitored by dynamic light scattering, exhibiting a spherical shape, a size of 30 to 100 nm (preferably 60 nanometers) and a zeta potential of -20 to -10 mV.

[54] The surface area of ​​the nanoparticles, calculated by the BET (Brunauer-Emmet-Teller) method, varies between 900 and 1000 cm2g-1, while the pore volume, calculated by the BJH (Barret-Joyner-Halenda) method, varies from 1.0 to 2.0 cm3 Petition 870260063790, dated 06 / 29 / 2026, page 16 / 61 13 / 23 g-1. The pore diameter varies between 2.0 and 10.0 nm.

[55] Other modifications can be made in order to functionalize the internal pores with phenyl groups, while the external surface is coated with reactive and / or ionizable groups (preferably with propylmethylphosphonate or propylamine).

[56] Thus, it is possible to produce chemically antagonistic regions in the same particle, with hydrophobic (inside) and hydrophilic (outside) regions, providing the possibility of simultaneously incorporating hydrophilic and hydrophobic molecules.

[57] Furthermore, there is the possibility of trapping molecules inside the pores by coating the nanoparticles with biomolecules (such as proteins and carbohydrates), which can increase the colloidal stability and biocompatibility of mesoporous silica nanoparticles. - Obtaining the biopolymer hydrogel:

[58] A block copolymer, preferably a block copolymer consisting of polyethylene oxide (PEO) and polypropylene oxide (PPO) monomers arranged in a PEO-PPO-PEO triblock structure (such as Pluronic F127), is solubilized in physiological saline to obtain a 30% (w / w) solution.

[59] For this, the physiological saline solution is placed in an ice water bath, under agitation, until thermal equilibrium is reached, without the temperature exceeding 4°C to 35°C, preferably 4°C. The copolymer is then added slowly under agitation. - Obtaining the hybrid system: Petition 870260063790, dated 06 / 29 / 2026, page 17 / 61 14 / 23

[60] The hybrid system is obtained by adding the mass of the drug to the copolymer solution in order to achieve a concentration between 0.01 mg ml-1 and 10 mg ml-1, preferably 1.25 mg ml-1 for DOX and 4.16 mg ml-1 for sildenafil, under agitation, in an ice water bath. More specifically, the antitumor drug is doxorubicin, which may or may not be associated with sildenafil.

[61] Mesoporous silica nanoparticles are suspended in deionized water and added last in order to avoid premature aggregation and flocculation.

[62] Furthermore, the corresponding volume of sodium chloride is also added to the system, so that a 0.9% saline system is obtained.

[63] The saline system is left in a refrigerator, at a temperature between 0 and 35 °C, preferably 4°C, under agitation overnight for complete solubilization of the copolymer. The gelation temperature of the systems ranged from 9 to 23°C.

[64] The stability of the nanoparticles in the presence of the block copolymer was tested by means of a colloidal stability assay and by evaluating the aggregation profile.

[65] The first assay consisted of a centrifugation study, mixing the nanoparticles in systems with different concentrations of the copolymer. The suspensions were centrifuged at different speeds for 5 minutes. The quantification of the nanoparticles was carried out by removing a volume of the supernatant after centrifugation and measuring its absorbance at 300 nm in a UV-Visible spectrophotometer. Petition 870260063790, dated 06 / 29 / 2026, page 18 / 61 15 / 23

[66] The second test consisted of monitoring particle size as a function of time using DLS. The nanoparticles were placed in contact with the copolymer and then the size of the nanoparticles and the polydispersity index were measured as a function of time at different copolymer concentrations.

[67] Thus, the hybrid system described in the invention comprises: - a reversible hydrogel of biocompatible polymer in a concentration of 5% to 25% (w:w), preferably 18%; - mesoporous silica nanoparticles at a concentration of 0.01 mg ml-1 to 10 mg ml-1, preferably 5 mg ml-1; and - drug in concentrations of 0.01 mg ml-1 to 10 mg ml-1, preferably 1.25 mg ml-1 for DOX and 4.16 mg ml-1 for sildenafil.

[68] The biocompatible polymer used is a block copolymer, preferably a block copolymer consisting of polyethylene oxide (PEO) and polypropylene oxide (PPO) monomers arranged in a PEO-PPO-PEO triblock structure, such as Pluronic F-127. The drugs comprise doxorubicin or sildenafil, which may be present simultaneously in the nanoparticle.

[69] Mesoporous silica nanoparticles have a spherical shape, a size of 30 to 100 nm (preferably 60 nanometers), and a zeta potential of -20 to -10 mV. The surface area of ​​the nanoparticles varies between 900 and 1000 cm2g1, while the pore volume varies from 1.0 to 2.0 cm3g-1 and the pore diameter varies between 2.0 and 10.0 nm.

[70] The hybrid system is applied in antitumor treatment, preferably in the treatment of cancer of Petition 870260063790, dated 06 / 29 / 2026, page 19 / 61 16 / 23 prostate. Tests performed: - Characterization of mesoporous silica nanoparticles:

[71] The nanoparticles were characterized by means of thermogravimetric analysis, Transmission Electron Microscopy (TEM), nitrogen adsorption-desorption isotherms and dynamic light scattering.

[72] After the synthesis of the nanoparticles, their concentration in suspension was calculated using their thermogram, illustrated in Figure 1.

[73] For this purpose, the mass loss at 300°C was taken into account, a point that guarantees the total elimination of water from the system. At this point, the remaining mass is attributed only to the silica present.

[74] As can be seen in Figure 1, at 300°C, only 1.92% of the initial mass remained. By comparative calculations with the initial silica values, it can be concluded that the silica concentration in the suspension is 17.79 mg ml-1. Starting from this suspension, new concentrations of 5 mg ml-1 and 10 mg ml-1 were obtained.

[75] Micrographs of mesoporous silica nanoparticles are illustrated in Figures 2A-C. The spherical morphology and the presence of pores are observed. Through analysis of the nanoparticle diameter, it was possible to observe a size distribution range of 50 and 80 nm, preferentially 60 nm.

[76] According to the results obtained in appropriate equipment, the total surface area is 970 cm2g-1, while the pore volume is 1.6 cm3g-1. Petition 870260063790, dated 06 / 29 / 2026, page 20 / 61 17 / 23

[77] The adsorption-desorption curve (see Figure 3) resembles a type IV isotherm, typical of mesoporous materials, in which initial adsorption is followed by capillary condensation. Also characteristic of this type of isotherm is the appearance of hysteresis curves which, in the case of the isotherm in Figure 3, is associated with the presence of uniform mesopores.

[78] The hydrodynamic radius of the particles obtained by DLS was 128.7 ± 4.718 nm, while the polydispersity index was 0.213 ± 0.03 and the zeta potential was -19.0 ± 2.9 mV. - Interactions of nanoparticles with antitumor drugs:

[79] The ability of doxorubicin (DOX) to incorporate into nanoparticles under different conditions was performed using the incorporation assay, incubating the nanoparticles with the drug, centrifuging and then measuring the absorbance at 480 nm of the supernatant.

[80] The incorporation efficiency was calculated as shown in Equation 1 and the incorporation capacity of silica was calculated as shown in Equation 2. The results are illustrated in Table 1. Efficiency = DOX mass in NPs / DOX mass added^ Equation 1 Capacity = 1 mass DOX in NPs' mass NPs x100 Equation 2 Table 1. Results of the DOX incorporation assay in nanoparticles (NP) Petition 870260063790, dated 06 / 29 / 2026, page 21 / 61 18 / 23 Sample DOX:NP (m:m) [DOX] (ug / ml) [NP] (ug / ml) DOXincorp (%) NP Capacity 1 0.25 62.5 250 63.2 ± 1.6 15.8 ± 0.4 2 0.50 125.0 250 54.8 ± 0.4 27.4 ± 0.2 3 0.75 187.5 250 45.2 ± 1.3 33.9 ± 1.0

[81] Observing the results of samples 1 to 5, which do not contain the copolymer, it is observed that, when increasing the amount of DOX in the system, the percentage of DOX incorporated in relation to the total mass of DOX in solution decreases, however, the amount of DOX incorporated per particle (represented by the NP capacity) increases.

[82] In samples with a lower DOX:NP ratio, there is a larger nanoparticle surface area available, causing the DOX adsorption efficiency per unit area to decrease. Conversely, in samples with a higher DOX:NP ratio, there is more DOX incorporated per particle.

[83] To evaluate the trend of the surface charge of the nanoparticles in contact with the drug, measurements of the zeta potential as a function of the DOX:NP ratio (m:m) were made, the results of which are shown in Table 2. Sample 6 consists of mesoporous silica nanoparticles in the absence of doxorubicin and PBS diluted 10 times as a dispersing medium. Table 2. Zeta potential assay of nanoparticles as a function of the DOX:NP ratio. Sample Ratio DOX:NP (m:m) Ç (mV) 1 1.25 +1.9 ± 2.8 2 1.00 -2.6 ± 0.3 Petition 870260063790, dated 06 / 29 / 2026, page 22 / 61 19 / 23 3 0.75 -6.5 ± 3.3 4 0.50 -14.3 ± 0.9 5 0.25 -17.1 ± 1.6 6 - -19.0 ± 3.0

[84] It is observed that, by increasing the amount of the antitumor drug, whose pKa is 9.2, the zeta potential of the mesoporous silica nanoparticles becomes increasingly positive. These results, combined with the incorporation results, indicate that there may be two sorption equilibria involving the drug and the surface of the nanoparticles: one for the internal pores and another for the external surface. It can be observed that, even for large amounts of DOX (higher DOX:NP ratios, such as 1.00 and 1.25), the zeta potential remains negative or slightly positive. The results suggest that part of the DOX present is adsorbed on the external surface of the nanoparticles and part in the internal pores, and this adsorption is dependent on the drug concentration in the system. - Behavior of nanoparticles in the presence of the copolymer:

[85] It was decided that the in vivo assay applications would be carried out in physiological saline so as not to induce a significant difference in osmotic pressure acting on peritoneal cells of the animals used in the in vivo tests.

[86] Thus, it was necessary to know whether the presence of the copolymer would stabilize the nanoparticles in the system, guaranteeing their integrity.

[87] For this purpose, a colloidal stability test was carried out, the results of which are illustrated in Figure 4. Petition 870260063790, dated 06 / 29 / 2026, page 23 / 61 20 / 23

[88] Since the copolymer has a small absorbance in the 2 63 nm region, the wavelength chosen to observe the presence of silica for all systems containing this copolymer was 300 nm.

[89] It is observed that polymer concentrations above 1% already promote the stabilization of nanoparticles, which increases with increasing copolymer concentration. With 10% copolymer, approximately 70% of particles remain in suspension after 5 minutes of centrifugation at 18400 rcf. These results indicate that nanoparticles are stable at copolymer concentrations above 1%.

[90] To evaluate the stability of nanoparticles in the presence of copolymer in relation to the aggregation rate as a function of time, the hydrodynamic radius and polydispersity index of nanoparticles were measured at different polymer concentrations at six times (1, 5, 10, 15, 30 and 60 minutes).

[91] The copolymer percentages (m:m) used were 0.01%, 0.05%, 0.10% and 1.00%. The aggregation profile results are illustrated (Figures 5A and 5B) by means of the increase in particle size at each time point relative to the particle size at time zero, which was 128.7 nm.

[92] The stability of nanoparticles in the presence of copolymers occurs through a balance of attraction or depletion repulsion. Particle aggregation occurs when depletion attraction overcomes repulsion.

[93] It is observed that, at low copolymer concentrations (Figure 5a), there is an increase in particle size as early as t = 1, indicating instability at these copolymer concentrations. All samples in Figure 5a Petition 870260063790, dated 06 / 29 / 2026, page 24 / 61 21 / 23 showed an increase of more than 10 times at the end of the trial.

[94] Conversely, concentrations above 0.10% stabilized the nanoparticles (Fig. 5b), showing little increase in particle size as a function of time, ranging from 0.2 to 0.5 times. - Dissolution of the hydrogel and release of the drug:

[95] To evaluate the drug release rate by the hybrid system, the membrane-free hydrogel dissolution method was used. The results were plotted and the slope of the line was taken as the hydrogel dissolution rate. The chosen delivery medium was a 1.0 mg ml-1 BSA solution, as it was desired to observe the DOX release profile in a medium containing biomolecules.

[96] It can be observed in the subsequent graphs (Figures 6A, 6B and 6C) that DOX is released as the gel dissolves. Particularly, for the third hybrid system described in figure 6C, it is possible to observe a greater difference between the gel dissolution and DOX release curves, indicating that the nanoparticles promote a sustained release of the drug. - In vivo application:

[97] In order to evaluate the copolymer's potential for prolonged drug release, as well as the role of nanoparticles in drug transport, six hybrid systems were developed, named: G1-DOX related to the system comprising 18% (w / w) of Pluronic F-127 and 1.25 mg / mL of DOX; G2-DOX related to the hybrid system comprising 18% (w / w) of Pluronic F-127, 1.25 mg / mL of DOX and 1 mg / mL of mesoporous nanoparticle Petition 870260063790, dated 06 / 29 / 2026, page 25 / 61 22 / 23 silica; G3-DOX related to the hybrid system comprising 18% (w / w) of Pluronic F-127, 1.25 mg / mL of DOX and 5 mg / mL of mesoporous silica nanoparticle; G1-SIL related to the system comprising 18% (w / w) of Pluronic F-127 and 4.16 mg / mL of sildenafil; G2-SIL related to the hybrid system comprising 18% (w / w) of Pluronic F-127, 4.16 mg / mL of sildenafil and 1 mg / mL of mesoporous silica nanoparticle; G3-SIL relates to the hybrid system comprising 18% (w / w) of Pluronic F-127, 4.16 mg / mL of sildenafil and 5 mg / mL of mesoporous silica nanoparticle.

[98] Thus, it was possible to evaluate the antitumor potential of the hybrid systems, obtaining information on the potential for prolonged release of the hydrogel with DOX and with SIL and on the role of mesoporous silica nanoparticles as drug carriers. Histopathological analyses of the ventral prostatic lobe of the animals showed that there was a decrease in the frequency of high-grade and intermediate-grade tumors as the nanoparticles were introduced and with the increase in their concentration, both for the systems containing DOX and for the systems containing sildenafil. The summary of the results of the histopathological analyses is found in Table 3. Table 3. Results of histopathological analyses HGPIN PIA Microacids Stromal hypertrophy Prostatic atrophy Tumor grade high intermediate low Cancer control 75% 25% - 25% - 25% 50% 25% Petition 870260063790, dated 06 / 29 / 2026, page 26 / 61 23 / 23 G1-DOX - - - - - - 100% - G2-DOX 66% - 100% - - - 66% 33% G3-DOX 100% - 100% - - - - 100% G1-SIL - - - - - - 100% - G2-SIL 66% - 100% 33% 66% - 33% 66% G3-SIL 100% 50% 100% 50% - - - 50%

[99] Thus, the hybrid systems proposed in this invention were effective in the treatment of chemically induced prostate cancer in rats and, as far as macroscopic observations are concerned, no cardiomegaly or macroscopic lesions in the heart and other usual side effects in treatments with doxorubicin were found. Petition 870260063790, dated 06 / 29 / 2026, page 27 / 61

Claims

1 / 4 CLAIMS 1. Process for obtaining a hybrid system based on biocompatible polymer hydrogels and mesoporous silica nanoparticles incorporated with antitumor drugs, characterized by comprising the steps of: a) Synthesis of mesoporous silica nanoparticles: a1) dissolving the cationic surfactant n-cetyltrimethylammonium bromide in an alkaline ammonium hydroxide solution at pH between 10 and 12, preferably 11; a2) homogenizing the solution by sonication for 1 to 30 minutes, preferably 10 minutes; a3) adding absolute ethanol to the solution obtained in step (a2) and stirring at 60 to 6000 rpm, preferably 300 rpm, for 5 to 30 minutes, preferably 15 minutes; a4) addition of tetraethoxylysane to the solution obtained in step (a3) ​​for chemical reaction for 1 to 3 hours, preferably 2 hours, at a temperature between 30 and 80°C, preferably 60°C;a5) Centrifugation of the solution obtained in step (a4) at 500 to 19000 rcf, preferably 18000 rcf, for 15 to 120 minutes, preferably 60 minutes, at temperatures between 4 and 35°C, preferably 4°C; a6) Suspension of the nanoparticles centrifuged in step (a5) in ethanol and storage at temperatures of 1 to 15°C, preferably 4°C; a7) Extraction of cetyltrimethylammonium from the nanoparticles obtained in step (a6), by adding absolute ethanol, homogenization in an ultrasonic bath for 5 to 30 minutes, preferably 5 minutes; and addition of analytical grade hydrochloric acid to the solution, homogenizing in an ultrasonic bath for 5 to 60 minutes, preferably 60 minutes; a8) centrifugation of the solution obtained in step (a7) for 15 to 120 minutes, preferably 60 minutes, with removal of the supernatant, washing with absolute ethanol twice, centrifugation of the solution at 500 to 19000 rcf, preferably 18000 rcf;and obtaining a suspension of mesoporous silica nanoparticles in absolute ethanol; b) Obtaining a biocompatible polymer solution: b1) solubilization of a block copolymer consisting of polyethylene oxide (PEO) and polypropylene oxide (PPO) monomers arranged in a PEO-PPO-PEO triblock structure in physiological saline to obtain a 30% (w / w) solution; b1.1) addition of physiological saline to a flask, under agitation, until thermal equilibrium is reached, maintaining the temperature at 0 to 35°C, preferably 4°C; b1.2) addition of the copolymer to the physiological saline obtained in step (b1.1) and its dissolution, maintaining the temperature at 0 to 35°C, preferably 4°C; to obtain a biocompatible polymer solution;c) Obtaining the hybrid system: c1) addition of doxorubicin and / or sildenafil drugs to the biocompatible polymer solution obtained in step (b1.2) in order to achieve a concentration of 1.25 mg mL-1 for doxorubicin and 4.16 mg mL-1 for sildenafil, under agitation, in a water bath with a temperature varying between 0 and 35°C, preferably 4°C; c2) addition of sodium chloride to the system obtained in step (c1), to obtain a 0.9% saline system; c3) suspension of the mesoporous silica nanoparticles, obtained in step (a8), in deionized water; c4) addition of the mesoporous silica nanoparticle suspension obtained in step (c3) to the saline system obtained in step (c2), under agitation at 60 to 6000 rpm, preferably 300 rpm, maintaining the temperature at 0 to 35°C, preferably 4°C, for 0 to 72 hours, preferably 48 hours, obtaining the hybrid system;and c5) gelation of the hybrid system, obtained in Petition 870260063790, dated 06 / 29 / 2026, page 53 / 61 4 / 4 step (c4), at room temperature, preferably between 5 and 25°C.; 2. Process, according to claim 1, characterized in that the internal pores of the nanoparticle are alternatively functionalized with hydrophobic organic functions of the phenyl type and the outer surface is coated with reactive and / or ionizable groups. Petition 870260063790, dated 06 / 29 / 2026, pp. 54 / 61

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