A tissue engineering scaffold serves as a substitute of the native extracellular matrix (ECM) and plays a crucial role in tissue regeneration by providing temporary support for cells during natural ECM formation. For tissue engineering applications, biodegradability, biocompatibility, non-inflammability and mechanical properties that match those of native tissue are some essential requirements to design a scaffold (Pryadko et al., 2022). Widespread research is being carried out on biomaterials for both experimental and therapeutic applications in tissue engineering. The prerequisite characteristic of scaffolds used in tissue engineering are high porosity and tunable bioactivity, such as good cell adhesion, proliferation and differentiation (Shuai et al., 2019). The development of polyhydroxyalknoates (PHA) derivatives is one of the feasible substrate options for biomedical applications and these eco-friendly polyesters are receiving flourishing consideration to be used as the most promising biomaterial to develop scaffold for tissue engineering (Gao et al., 2017). PHAs have demonstrated admirable biocompatibility with cell types like osteocytes, fibroblasts, stem cells, chondrocytes and keratinocytes and are used as a recommended matrix material for growth and proliferation of various mammalian cells (Mohandas et al., 2021).

The poly [(R)− 3-hydroxybutyric acid] (PHB) is the first and most common member of the PHA family (Feng et al., 2018). In vitro hydrolysis of PHB generates the monomer D-3-hydrobutyric acid, which is a typical component of human blood, is nontoxic when present in body fluids and shows no inflammatory effects. Therefore, it is thought that PHB can be well tolerated in the in vivo systems (Anjum et al., 2016). The biocompatibility, biodegradability, non- immunogenicity and thermoplasticity with good tunable morphology and mechanical properties make it a suitable biomaterial for tissue engineering applications (Kovalcik et al., 2020, Dhania et al., 2022). However, the lack of hydrophilic functional group and homogeneity in PHB networks depicts high degree of crystallinity which makes the material rigid and stiff, thus, rendering it less suitable for cells to adhere upon thus limiting its applications (Ochoa-Segundo et al., 2020). This can be overcome by adopting the approach of blending of some other polymers to obtain desired results. For instance, blending of PHBV with PHB can decrease the melting temperature of the material, allowing them to be processed at lower temperatures in order to generate precise anatomical forms while limiting or avoiding degradation (Masaeli et al., 2013). PHBV (Poly(3-hydroxybutyric acid-co-3-hydrovalric acid)), the copolymer of PHB with 3-hydroxy valerate units (3-HV), expedite the enhancement of mechanical and physico-chemical properties of polymer (Mohandas et al., 2021). The 3-hydroxyvalerate moiety in the structure improves the material properties, namely, biocompatibility, easy processibility, and propensity to biodegradation in diverse environmental condition (Liu et al., 2014). They have also been shown to improve the impact strength, however this is also accompanied by a reduction in tensile strength and modulus (McAdam et al., 2020). As a result, PHBV and PHB can be combined to create a scaffold with better physical and mechanical attributes along with cell adhesion, proliferation, and degradation features (Masaeli et al., 2013).

Various methods have been reported for the preparation of scaffolds include freeze-drying, gas foaming, solvent casting-particulate leaching, melt molding-particulate leaching, thermally induced phase separation and electrospinning. An excellent technique for fabrication of porous scaffolds, which serve as a temporary template and provide a surface for cell adhesion, mechanical support, and guidance of the regeneration processes, is solvent casting particulate leaching (Puppi et al., 2017). The technique entails mixing of water-soluble solid particles (like sodium chloride and calcium chloride) in the polymer matrix and their consecutive removal with its solvent (like water), resulting in the formation of porous network all across the polymer matrix (Nahanmoghadam et al., 2021, Zonta et al., 2021).

To the best of our knowledge, salt leaching technique has not been used to synthesize scaffolds with different PHB and PHBV ratios, and our findings highlighted how well-suited blended scaffolds are for use in tissue engineering applications. The technique enhanced the surface hydrophilicity and wettability of the fabricated scaffolds. Previous research has shown that cells are more likely to adhere to hydrophilic surfaces and also surface wettability directly related to cell adhesion which further related to hydrophilic surfaces supporting better cell adhesion than hydrophobic surfaces (Hasan et al., 2018). Therefore, in an attempt to associate the advantages and get around the disadvantages of PHB and PHBV as singles, both the polymers are blended in different ratios to fabricate porous scaffolds for tissue engineering by means of cost-effective simple salt leaching technique. The resulting scaffolds underwent tests to determine their hemocompatibility, cell cytocompatibility, cell adhesion and proliferation potential by characterizing their pore structure, morphology, wettability and melting behavior.