Periodontitis is a chronic inflammatory disease driven by microbial biofilms, resulting in the progressive destruction of periodontal tissues, including the gingiva, periodontal ligament, and alveolar bone [1]. It represents a significant global health challenge, with the World Health Organization [2] estimating that severe periodontitis affects around 10.8 % of the adult population, making it the eleventh most prevalent disease worldwide. Moreover, oral diseases as a whole are projected to become the sixth most common health condition by 2030, underscoring the growing global burden of dental and periodontal disorders [2], [3].

Traditional treatment modalities, including scaling and root planing, aim to control infection and inflammation but often fall short in achieving complete tissue regeneration, particularly in cases of advanced bone loss [4], [5], [6]. Guided tissue regeneration (GTR) has emerged as a promising strategy to restore periodontal structures, relying on barrier membranes to prevent epithelial migration and promote the repopulation of periodontal ligament and bone cells [4], [5]. However, existing membranes face significant limitations, such as inadequate biodegradability, poor mechanical properties, and a lack of antimicrobial activity, which can compromise their clinical efficacy [4].

In recent years, tissue engineering has revolutionized regenerative dentistry by offering innovative solutions to overcome these challenges [7], [8]. Previous research has demonstrated the potential of nanobiomaterials, bioprinted and electrospun scaffolds for regenerative medicine applications [9], [10], [11], [12]. Electrospun nanofibrous scaffolds have gained prominence due to their ability to mimic the extracellular matrix (ECM), providing a favorable microenvironment for cell adhesion, proliferation, and differentiation [4], [5], [6]. Among the polymers used for scaffold fabrication, poly(L-co-D,L lactic acid) (PLDLA) stands out for its biodegradability, biocompatibility, and tunable mechanical properties [13], [14], [15], [16], [17]. The incorporation of nanostructured carriers has enhanced scaffold performance by improving bioactivity and supporting cell adhesion, proliferation, and differentiation. To further potentiate their regenerative capacity, bioactive components such as nano-hydroxyapatite (nHA) and antimicrobial agents like chlorhexidine have been integrated, providing both osteoinductive and antibacterial functionalities [4], [5].

Nano-hydroxyapatite (nHA), a biomimetic form of the mineral component of bone, not only supports osteoinduction and mineralization but also contributes to structural stability in engineered scaffolds [18], [19], [20], [21]. Conventional sources of nHA often involve synthetic or mined materials, which raise environmental and cost concerns [18], [19], [20], [21], [22], [23]. In this context, the recycling of marine waste, such as oyster and mussel shells, presents a sustainable alternative [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41]. These shells, composed primarily of calcium carbonate, can be converted into high-purity nHA through controlled chemical processes, addressing both environmental waste management and the demand for biomaterials [36], [37], [38], [39], [40].

The integration of antimicrobial agents into scaffolds is critical to prevent bacterial colonization and biofilm formation, which are major obstacles to successful periodontal regeneration [4], [5]. Chlorhexidine, a broad-spectrum antimicrobial agent, has been widely used in dentistry for its efficacy against periodontal pathogens [36]. However, its conventional formulations may exhibit cytotoxicity or limited sustained release.

Nanocarrier-based release systems represent a promising approach in biomedical engineering due to their high surface area, kinetic stability, and enhanced penetration properties. These systems offer significant advantages over traditional formulations, including controlled active release, the ability to solubilize lipophilic active ingredients in aqueous media, increased physicochemical stability, and potential reduction of side effects and toxicity [42], [43], [44]. Specifically, the nanoemulsified formulation of chlorhexidine (nCHX) is crucial for ensuring improved drug stability, bioavailability, and controlled release, thereby optimizing its antimicrobial efficacy. Its nanoscale nature further facilitates uniform distribution within electrospun polymeric matrices, which is critical for optimized and controlled drug release in dental applications.

This study aims to develop and characterize biodegradable nanofibrous scaffolds composed of PLDLA, functionalized with nHA derived from recycled mussel shells and nCHX. The proposed scaffolds are designed to address key clinical challenges in GPR by combining antimicrobial activity, biocompatibility, and osteogenic potential in a single multifunctional platform. The use of marine waste not only aligns with principles of sustainability and circular economy but also provides a cost-effective source of biomaterials [24], [25], [26], [27], [28], [29], [30]. The scaffolds were evaluated for their physicochemical properties, biocompatibility, antimicrobial activity, and osteoinductive potential. The findings of this study hold significant implications for the development of next-generation biomaterials that integrate sustainability, functionality, and clinical efficacy.