Synergistic Effects of Silver Nanoparticles with Tamoxifen for Breast Cancer: A Review

INTRODUCTION
Breast cancer remains one of the leading causes of cancer-related mortality toxicity, and variable patient responses necessitate the development of innovative worldwide, demanding continuous advancements in therapeutic strategies to improve patient outcomes [1]. Conventional treatment approaches—including surgery, radiation therapy, chemotherapy, and endocrine therapy have significantly contributed to disease management. However, challenges such as drug resistance, systemic solutions that enhance therapeutic efficacy while minimizing adverse effects [2]. Among endocrine-based therapies, tamoxifen has been a cornerstone in treating estrogen receptor-positive (ER+) breast cancer, functioning as a selective estrogen receptor modulator (SERM) to inhibit tumor progression. Despite its widespread clinical use, tamoxifen therapy is often associated with acquired resistance, leading to treatment failure and recurrence in a substantial subset of patients [3]. In recent years, nanotechnology has emerged as a promising avenue for cancer therapy, offering solutions that optimize drug delivery, enhance bioavailability, and improve treatment specificity. Nanoparticles, particularly metallic nanostructures, have gained attention for their ability to modulate biological interactions at the cellular level [4]. Silver nanoparticles (AgNPs) are among the most extensively studied metallic nanoparticles due to their intrinsic antimicrobial, anti-inflammatory, and anticancer properties. Their ability to induce apoptosis, generate reactive oxygen species (ROS), and disrupt cellular metabolism makes them attractive candidates for combination therapies in oncology. Given their systemic toxicity [5].
The potential synergy between AgNPs and tamoxifen presents an opportunity to enhance breast cancer treatment outcomes. While tamoxifen targets estrogen receptor signaling, AgNPs contribute additional anticancer effects through oxidative stress induction and mitochondrial dysfunction, thereby amplifying therapeutic response. This combinatorial approach may offer several advantages, including lower drug doses, reduced toxicity, and improved tumor selectivity [6]. 
This review provides a comprehensive analysis of the mechanistic interplay between AgNPs and tamoxifen, focusing on their synergistic effects in breast cancer therapy. By examining synthesis methods, physicochemical characteristics, biological interactions, and preclinical findings, we aim to highlight the potential translational impact of this novel combinatorial strategy. Through a structured evaluation of existing literature and experimental insights, we seek to present an informed perspective on the viability of AgNP-assisted tamoxifen therapy as a precision-targeted approach in breast cancer treatment.

SILVER NANOPARTICLES: SYNTHESIS AND PROPERTIES
Common Synthesis Methods
Silver nanoparticles have been synthesized using various methods that significantly influence their physicochemical characteristics, stability, and suitability for drug delivery applications. These approaches are broadly categorized into chemical, biological, and green synthesis methods, each with distinct advantages and limitations in biomedical and pharmaceutical research. The selection of an appropriate synthesis technique depends on factors such as particle uniformity, scalability, biocompatibility, and environmental sustainability [7]. Chemical synthesis is the most commonly employed method due to its ability to precisely control nanoparticle size, shape, and surface properties [8]. This approach typically involves the reduction of silver salts, most commonly silver nitrate, in the presence of chemical reducing agents such as sodium borohydride, citrate, or ascorbic acid. The reaction proceeds under controlled conditions, where the concentration and type of reducing agent determine nanoparticle formation kinetics and final morphology [9]. Stabilizers such as polyvinylpyrrolidone, polyethylene glycol, or citrate are incorporated to prevent aggregation and enhance colloidal stability [10]. However, while chemical synthesis ensures reproducibility and scalability, residual reducing agents and stabilizers may introduce toxicity concerns, requiring extensive purification before biological applications [11].
Biological synthesis, also referred to as biosynthesis, employs microorganisms, plant extracts, or biomolecules to facilitate silver ion reduction and nanoparticle stabilization. Bacteria such as Pseudomonas aeruginosa and Bacillus subtilis and fungi like Aspergillus niger secrete extracellular metabolites that catalyze the conversion of silver ions into stable nanoparticles [12]. Plant-mediated synthesis utilizes phytochemicals such as flavonoids, alkaloids, terpenoids, and phenolic compounds to drive nanoparticle formation without synthetic chemicals. This approach enhances the biocompatibility of silver nanoparticles, making them more suitable for biomedical applications. However, challenges such as variability in natural reducing agents, reaction reproducibility, and batch-to-batch consistency remain key limitations that need further optimization [13].
Green synthesis represents an advancement in eco-friendly nanotechnology by integrating natural reducing and stabilizing agents to minimize the use of toxic chemicals. Polyphenol-rich plant extracts, algae-derived biomolecules, and biodegradable polymers such as chitosan serve as reducing agents, ensuring a sustainable reaction process [14]. By eliminating synthetic reagents, green synthesis improves biocompatibility and reduces cytotoxicity risks. However, factors such as temperature control, pH optimization, and precursor concentration require careful standardization to achieve consistent nanoparticle characteristics suitable for drug delivery [15].

Physicochemical Properties Relevant to Drug Delivery
The physicochemical properties of silver nanoparticles play a crucial role in their biological interactions, drug-loading capacity, cellular uptake, and overall efficacy in therapeutic applications [16]. Key factors such as particle size, morphology, surface charge, stability, and biocompatibility determine their behavior in physiological environments and their suitability for targeted drug delivery [17]. Particle size is a critical parameter that influences nanoparticle biodistribution and cellular interactions. Silver nanoparticles typically range from one to one hundred nanometers, with smaller nanoparticles exhibiting enhanced permeability across biological membranes [18]. Nanoparticles show optimal cellular uptake via receptor-mediated endocytosis, ensuring efficient drug transport to target sites. Size-dependent interactions affect drug release kinetics, clearance rates, and accumulation at diseased tissues. The enhanced permeability and retention effect, which allows nanoparticles to preferentially accumulate in tumor tissues due to leaky vasculature, is largely dependent on nanoparticle size [19]. Silver nanoparticles can exhibit diverse morphologies, including spherical, rod-shaped, triangular, and cubic forms, each influencing their interaction with cells and tissues [20]. Spherical nanoparticles are widely used due to their high uptake efficiency and colloidal stability, whereas rod-shaped nanoparticles display increased surface contact with biological membranes, promoting enhanced cellular adhesion [21]. The morphology of silver nanoparticles affects their circulation time and interaction with drug carriers, influencing drug release profiles and treatment efficacy [16]. Surface charge dictates nanoparticle interactions with biological membranes, serum proteins, and cellular receptors. Positively charged nanoparticles display strong electrostatic attraction toward negatively charged cellular membranes, facilitating uptake and internalization into tumor cells[22] . However, excessive positive charge can lead to membrane disruption and cytotoxicity, necessitating careful modulation. Negatively charged or neutral nanoparticles tend to exhibit improved circulation stability, reduced nonspecific interactions, and lower immunogenicity [23]. Surface functionalization with polyethylene glycol, albumin, or biocompatible polymers enhances nanoparticle stability and prolongs systemic circulation, ensuring effective drug delivery to diseased tissues [24]. Nanoparticle stability is essential for maintaining colloidal dispersion in physiological fluids. Aggregation tendencies can compromise drug loading efficiency and alter therapeutic response. Stabilizing agents such as dextran, chitosan, and polysaccharides improve nanoparticle dispersion, preventing clumping and degradation in biological environments [25]. Biodegradability is another factor influencing pharmacokinetics and clearance mechanisms. Silver nanoparticles with controlled degradation profiles ensure sustained drug release, reducing systemic toxicity while enhancing therapeutic efficacy [26]. Silver nanoparticles designed for combination therapies with conventional drugs, such as tamoxifen, must exhibit finely tuned physicochemical properties to optimize tumor selectivity, enhance cytotoxic effects, and ensure therapeutic precision [27].

MECHANISMS OF ACTION OF SILVER NANOPARTICLES
Anticancer Properties of Silver Nanoparticles
Silver nanoparticles exert cytotoxic effects on cancer cells through multiple biochemical pathways, primarily mediated by oxidative stress induction, mitochondrial disruption, and alterations in cellular signaling networks [28]. One of the primary mechanisms involves excessive generation of reactive oxygen species, leading to oxidative imbalance in cancer cells. This process disrupts intracellular antioxidant defenses, particularly the glutathione system, making malignant cells highly susceptible to oxidative damage [29]. Increased reactive oxygen species levels initiate lipid peroxidation, DNA fragmentation, and protein oxidation, collectively impairing cellular function and promoting apoptosis. The apoptotic response is further reinforced by the activation of intrinsic mitochondrial pathways, involving depolarization of the mitochondrial membrane, release of cytochrome c into the cytosol, and subsequent caspase cascade activation, culminating in programmed cell death [30]. Apart from oxidative damage, silver nanoparticles modulate cell cycle progression by inducing arrest at the G2/M checkpoint. This inhibition is associated with DNA damage response activation, wherein p53 stabilization leads to upregulation of cyclin-dependent kinase inhibitors such as p21. The resulting cell cycle blockade prevents mitotic progression, inhibiting proliferation and reducing tumor expansion [31]. 

Estrogen Receptor Modulation by Tamoxifen
Tamoxifen functions as a selective estrogen receptor modulator, primarily targeting estrogen receptor-positive breast cancer cells by competitively binding to estrogen receptors. The estrogen receptor, upon activation by endogenous ligands, regulates gene transcription essential for cell proliferation and survival [32]. Tamoxifen acts as an antagonist by occupying the ligand-binding domain of the estrogen receptor, thereby preventing estrogen-induced conformational changes necessary for transcriptional activation. The interference with estrogen receptor signaling diminishes proliferative stimuli and induces growth suppression in hormone-sensitive tumor cells [33]. Beyond its role as an estrogen receptor antagonist, tamoxifen exerts apoptotic effects through mitochondrial dysfunction. Tamoxifen-induced apoptosis involves disruption of mitochondrial membrane integrity, leading to loss of membrane potential and release of pro-apoptotic factors such as cytochrome [34]. This initiates the caspase cascade, resulting in cell death independent of estrogen receptor activity. Furthermore, tamoxifen modulates secondary signaling pathways that contribute to tumor progression. Inhibition of the phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase pathways disrupts pro-survival signaling and enhances sensitivity to cytotoxic stimuli [35]. Despite its efficacy, prolonged tamoxifen treatment is associated with acquired resistance, often due to estrogen receptor mutations, altered co-regulator recruitment, and activation of compensatory growth pathways. The development of resistance necessitates combinatorial approaches to improve therapeutic response [36]. Silver nanoparticles provide an alternative strategy to counteract resistance mechanisms by exerting independent cytotoxic effects that bypass estrogen receptor signaling. The integration of silver nanoparticles with tamoxifen offers a dual-action approach, where oxidative stress-induced damage complements hormonal blockade, enhancing treatment outcomes while reducing the likelihood of resistance development [37].

ROLE OF TAMOXIFEN IN BREAST CANCER
Mechanism of Action as a Selective Estrogen Receptor Modulator
Tamoxifen is a non-steroidal triphenylethylene derivative that functions as a selective estrogen receptor modulator in the treatment of estrogen receptor-positive breast cancer. It exerts its therapeutic effect by competitively binding to the estrogen receptor, preventing the activation of estrogen-induced transcriptional pathways that regulate tumor cell proliferation, survival, and metastatic potential [38]. The estrogen receptor is a nuclear hormone receptor that, upon activation by estrogen, undergoes conformational changes that facilitate dimerization and subsequent binding to estrogen response elements in the promoter regions of target genes [39]. This interaction leads to the recruitment of coactivator proteins such as steroid receptor coactivator-1 and activator protein-1, which are essential for transcriptional activation. Tamoxifen binds to the ligand-binding domain of the estrogen receptor, inducing an alternative conformational state that prevents coactivator recruitment while promoting corepressor interactions, leading to inhibition of estrogen-responsive gene expression [40]. The blockade of estrogen receptor signaling by tamoxifen leads to alterations in cell cycle progression, with significant downregulation of genes responsible for proliferation and survival. Cyclin D1, a key regulator of the transition from the G1 phase to the S phase, is suppressed, leading to impaired DNA synthesis and cell cycle arrest [41]. Tamoxifen also modulates apoptotic pathways by upregulating pro-apoptotic proteins such as BAX while downregulating anti-apoptotic factors like BCL-2. These molecular changes promote programmed cell death, reducing tumor burden and enhancing treatment efficacy [42]. Beyond its direct estrogen receptor antagonistic effects, tamoxifen influences non-genomic pathways involved in breast cancer progression. Growth factor signaling, including the epidermal growth factor receptor and insulin-like growth factor pathways, is disrupted by tamoxifen-mediated inhibition of estrogen receptor cross-talk. This results in decreased activation of downstream kinases such as AKT and extracellular signal-regulated kinase, which are responsible for cell survival and resistance mechanisms [43]. Tamoxifen’s tissue-specific activity allows it to function as an estrogen antagonist in breast tissue while exhibiting partial agonistic effects in other tissues, including the endometrium, bone, and cardiovascular system [44].

Drug Resistance and Side Effects
Tamoxifen resistance is a major challenge in the long-term management of hormone receptor-positive breast cancer, occurring in both early-stage and advanced disease. Resistance mechanisms are multifactorial, involving genetic, epigenetic, and metabolic adaptations that alter drug responsiveness [45]. One of the primary drivers of tamoxifen resistance is the emergence of estrogen receptor mutations, particularly in the ligand-binding domain. Mutations in the ESR1 gene lead to constitutive receptor activation independent of estrogen, allowing tumor cells to bypass tamoxifen-mediated inhibition. These mutations are commonly observed in metastatic breast cancer and are associated with decreased treatment efficacy and increased disease progression [46]. Another contributor to resistance is the activation of compensatory signaling pathways that promote estrogen-independent proliferation. Growth factor pathways such as epidermal growth factor receptor, insulin-like growth factor, and fibroblast growth factor signaling become upregulated in resistant tumors, driving activation of pro-survival kinases such as AKT and MAPK. The downstream effects of these pathways include enhanced tumor cell proliferation, invasion, and evasion of apoptosis, ultimately reducing tamoxifen efficacy [47]. Changes in coactivator and corepressor recruitment further impact tamoxifen response. Increased expression of steroid receptor coactivator-1 and activator protein-1 can override tamoxifen-induced repression of estrogen-dependent transcription, allowing continued tumor growth despite endocrine therapy. Conversely, reduced expression of nuclear corepressor proteins can impair tamoxifen’s ability to suppress estrogen receptor activity, contributing to treatment failure [48]. Epigenetic modifications, including DNA methylation and histone acetylation, also play a role in tamoxifen resistance. Aberrant hypermethylation of estrogen receptor target gene promoters can lead to silencing of tumor-suppressor genes while histone modifications alter chromatin accessibility, facilitating drug-resistant phenotypes [49]. Tamoxifen significantly increases the risk of thromboembolic events due to its partial estrogen agonistic effects in vascular endothelial cells, leading to enhanced coagulation factor activation. Deep vein thrombosis and pulmonary embolism are among the most serious complications, necessitating careful patient monitoring and risk assessment [50]. Endometrial changes, including hyperplasia, polyp formation, and an increased risk of endometrial cancer, occur due to tamoxifen’s agonistic activity in uterine tissue. This effect is mediated by estrogen receptor activation in the endometrial lining, promoting aberrant cellular proliferation. Postmenopausal patients receiving tamoxifen require regular gynecological evaluations to assess endometrial health [51].

SYNERGISTIC INTERACTIONS BETWEEN SILVER NANOPARTICLES AND TAMOXIFEN
Synergistic Effects and Mechanisms
The interaction between silver nanoparticles and tamoxifen in breast cancer therapy represents a promising strategy to overcome therapeutic limitations associated with endocrine resistance and poor drug efficacy. While tamoxifen primarily targets estrogen receptor-positive breast cancer cells by competitively inhibiting estrogen receptor signaling, silver nanoparticles exhibit independent cytotoxic effects through mechanisms such as oxidative stress induction, mitochondrial dysfunction, cell cycle disruption, and interference with tumor survival pathways. The combination of these agents results in a synergistic effect that enhances apoptosis, improves therapeutic selectivity, and reduces the risk of treatment failure due to drug resistance [52]. One of the mechanisms underlying the synergy between silver nanoparticles and tamoxifen involves disruption of compensatory pathways that mediate hormone therapy resistance [53]. Breast cancer cells frequently develop adaptive survival mechanisms through the activation of growth factor-mediated signaling pathways, such as phosphoinositide 3-kinase, mitogen-activated protein kinase, and epidermal growth factor receptor pathways [54]. These compensatory mechanisms enable tumor cells to evade tamoxifen-induced estrogen receptor inhibition by activating alternative proliferative and anti-apoptotic pathways [55]. Silver nanoparticles counteract these resistance mechanisms by promoting oxidative imbalance, leading to extensive cellular damage that compromises compensatory signaling, thereby restoring tamoxifen sensitivity [56]. Oxidative stress plays a significant role in the cytotoxicity of silver nanoparticles. While normal cells maintain a tightly regulated redox balance, cancer cells often exhibit elevated antioxidant defense mechanisms to counteract the increased metabolic activity associated with rapid proliferation [57]. These adaptations, including upregulation of glutathione, catalase, and superoxide dismutase, allow tumor cells to resist apoptosis induced by oxidative damage [58]. Silver nanoparticles disrupt this balance by generating excessive reactive oxygen species, leading to irreversible damage to cellular structures, including lipids, proteins, and nucleic acids [29].

Enhanced Apoptosis and Cytotoxicity
Tamoxifen primarily induces apoptosis by suppressing estrogen receptor-mediated transcription and activating mitochondrial-dependent apoptotic cascades, while silver nanoparticles reinforce these effects by inducing extensive oxidative stress, metabolic dysfunction, and proteomic damage [59]. A major component of this enhanced apoptosis involves modulation of key apoptotic regulators. Silver nanoparticles have been shown to upregulate pro-apoptotic proteins such as BAX while suppressing anti-apoptotic factors including BCL-2 and survivin. The shift in apoptotic regulatory protein expression enhances mitochondrial permeability transition, resulting in cytochrome c release and subsequent activation of caspase-9 and caspase-3, the central executioners of apoptosis. This effect synergizes with tamoxifen-mediated apoptotic responses, amplifying the therapeutic impact [60]. Beyond apoptotic mechanisms, silver nanoparticles contribute directly to tumor cytotoxicity by disrupting metabolic processes essential for cancer cell survival. Breast cancer cells exhibit high metabolic demand due to their rapid proliferative nature, relying heavily on glycolysis and oxidative phosphorylation to sustain energy production [61]. Silver nanoparticles interfere with glucose uptake by inhibiting glucose transporter proteins and downregulating glycolytic enzymes such as hexokinase and pyruvate kinase. This metabolic disruption leads to adenosine triphosphate depletion, impairing tumor cell survival and enhancing the cytotoxic effects of tamoxifen therapy [62]. Silver nanoparticles also exert anti-angiogenic effects by suppressing vascular endothelial growth factor expression and impairing endothelial cell migration, reducing tumor vasculature development. Tamoxifen-resistant breast cancer cells frequently upregulate vascular endothelial growth factor expression to maintain angiogenesis despite endocrine therapy [63]. Silver nanoparticles inhibit this process, depriving tumor cells of essential nutrients and oxygen supply, further enhancing cytotoxicity. Additionally, silver nanoparticles modulate immune response by stimulating macrophage activation and cytokine production. The inflammatory microenvironment induced by silver nanoparticle treatment enhances tumor clearance by activating immune surveillance mechanisms, further complementing tamoxifen’s apoptotic effects [64].

Clinical Studies 
Seyed Naser Ostad et al [65], investigated the ability cytotoxic impact of silver nanoparticles (Ag NPs) and silver ions (Ag+) in each determine and tamoxifen-resistant T47D cells in presence and absence of tamoxifen. As a separate test, the impact of subinhibitory concentrations of Ag NPs and Ag+ on the proliferation of tamoxifen-resistant cells become evaluated at non-toxic concentrations of tamoxifen. consequences counseled that during non-cytotoxic concentrations of silver nanomaterials and tamoxifen, the combinations of Ag+-tamoxifen and Ag NPs-tamoxifen are still cytotoxic. This locating can be of great capacity gain in chemotherapy of breast most cancers; given that tons lower doses of tamoxifen may be had to produce the identical cytotoxic impact and facet consequences may be reduced.
Maria D Rivera et al [6], conducted a complete nanotoxicological assessment of strategic combinations regarding AgNPs (68 nm) business system and tamoxifen on MCF-7 and MDA-MB-231 breast tumor cells. making use of CompuSyn software, the aggregate index was decided, revealing a synergistic cytotoxic and antiproliferative effect in AgNPs and tamoxifen mixtures (CI < 0.97). both breast tumor cellular strains exhibited extended proapoptotic and oxidative pressure gene expression following the mixed treatment. The internalization of AgNPs into breast most cancers cells turned into observed, improving their synergistic antiproliferative effect while combined with tamoxifen. those findings recommend the capacity of mixing AgNPs with chemotherapeutic agents for innovative studies in oncology therapy.
M Rasheed et al [66], synthesized therapeutic silver nanoparticles by the discount of steel salt through tea extract within the presence of Tamoxifen. The cytotoxicity of Tamoxifen capped inexperienced tea decreased nanoparticles (TAM-AgNPs) turned into discovered to growth and the effect changed into co-related with decreased expression of an enzyme, referred to as O-GlcNAc Transferase (OGT). This suggests that, OGT can be targeted as capability therapeutic candidate and a detailed pastime mechanism of OGT needs to be further explored as it has function in growing the efficacy of drug delivery.

CONCLUSION AND FUTURE PERSPECTIVES 
The synergistic interaction between silver nanoparticles and tamoxifen presents a promising approach for enhancing the therapeutic efficacy of breast cancer treatment. Tamoxifen, as a selective estrogen receptor modulator, has played a crucial role in managing estrogen receptor-positive breast cancer by blocking estrogen-induced tumor proliferation. However, resistance to tamoxifen remains a significant clinical challenge, often mediated by secondary signaling pathways, estrogen receptor mutations, and adaptive metabolic changes in tumor cells. Silver nanoparticles introduce a complementary mechanism of cytotoxicity by generating oxidative stress, disrupting mitochondrial function, and interfering with proliferative signaling networks. The combination of these agents results in amplified apoptotic responses, reduced metabolic adaptation, and improved tumor suppression.
Through extensive research into the molecular interactions between silver nanoparticles and tamoxifen, several mechanistic pathways have been identified that contribute to enhanced therapeutic outcomes. These include the modulation of apoptotic regulatory proteins, increased mitochondrial destabilization, inhibition of angiogenic signaling, disruption of glycolytic metabolism, and immune modulation. The ability of silver nanoparticles to sensitize cancer cells to tamoxifen-mediated apoptosis highlights their potential as adjunct therapies in breast cancer management. Furthermore, nanoparticle functionalization and controlled drug release mechanisms offer new opportunities for improving bioavailability and reducing systemic toxicity.
Despite the promising findings, challenges remain in optimizing nanoparticle-based delivery systems for clinical applications. Factors such as nanoparticle stability, biodistribution, biocompatibility, and long-term safety require further investigation. Standardization of synthesis protocols and dose optimization strategies will be critical for ensuring reliable therapeutic efficacy while minimizing adverse effects. The complexity of nanoparticle-tumor interactions necessitates detailed pharmacokinetic and pharmacodynamic studies to understand their behavior in vivo.
The combination of silver nanoparticles and tamoxifen represents an evolving area of research in nanomedicine and targeted drug delivery for breast cancer therapy. Future studies should focus on refining nanoparticle functionalization strategies to achieve precise drug release and tumor targeting capabilities. Surface modifications with tumor-specific ligands, polyethylene glycol coatings, or biomolecular conjugates can enhance nanoparticle retention in cancer cells while reducing off-target effects.
Advanced nanocarrier platforms, including hybrid nanoparticle systems incorporating multiple therapeutic agents, may offer improved treatment outcomes by simultaneously targeting multiple pathways involved in tamoxifen resistance. The incorporation of additional molecular inhibitors, such as cyclin-dependent kinase inhibitors or histone deacetylase inhibitors, could further enhance the therapeutic potential of nanoparticle-assisted endocrine therapy.
Furthermore, integrating silver nanoparticles into combination regimens with immunotherapeutic agents may provide opportunities to modulate the tumor microenvironment and stimulate immune-mediated clearance of cancer cells. The immune-modulating effects of silver nanoparticles, including macrophage activation and cytokine release, suggest their potential role in complementing immune checkpoint inhibitors for breast cancer treatment.
Clinical translation will require systematic toxicity assessments, regulatory approval processes, and large-scale in vivo validation studies to confirm the safety and efficacy of silver nanoparticle-based therapies. Establishing standardized guidelines for nanoparticle synthesis, dosage formulation, and administration protocols will be critical for facilitating the integration of these technologies into routine clinical practice.
As research continues to advance, nanoparticle-assisted drug delivery systems may redefine the landscape of breast cancer treatment by offering more precise, efficient, and personalized therapeutic options. With continued efforts in biomedical engineering, molecular oncology, and clinical research, silver nanoparticles combined with tamoxifen hold significant promise in addressing endocrine resistance and improving survival outcomes for patients with estrogen receptor-positive breast cancer.

CONFLICT OF INTEREST
The authors declare that there is no conflict of interests regarding the publication of this manuscript.