Introduction: The current study, for the first time, suggests nature-made pollen grains (PGs) of Pistacia vera L. as a potential candidate for using as scaffolding building blocks with encapsulation capability of bioactive compounds, such as bone morphogenetic protein 4 (BMP4). Methods: A modified method using KOH (5%, 25º C) was developed to produce nonallergic hollow pollen grains (HPGs), confirmed by energy dispersive X-ray (EDX) analysis, field emission scanning electron microscopy (FESEM), and DNA and protein staining techniques. The in-vitro study was conducted on human adipose-derived mesenchymal stem cells (hAD-MSCs) to investigate the applicability of HPGs as bone scaffolding building blocks. Cytocompability was evaluated by FESEM, MTT assay, and gene expression analysis of apoptotic markers (BAX and BCL2). The osteoconductive potential of HPGs was assessed by alkaline phosphatase (ALP) activity measurement and gene expression analysis of osteogenic markers (RUNX2 and osteocalcin). Results: Findings demonstrated that HPGs can be considered as biocompatible compounds increasing the metabolic activities of the cells. Further, the bioactive nature of HPGs resulted in suitable cellular adhesion properties, required for a potent scaffold. The investigation of apoptotic gene expression indicated a reduced BAX/BCL2 ratio reflecting the protective effect of HPGs on hAD-MSCs. The increased ALP activity and expression of osteogenic genes displayed the osteoconductive property of HPGs. Moreover, the incorporation of BMP4 in HPGs initiated a synergistic effect on osteoblast maturation. Conclusion: Owing to the unique compositional and surface nanotopographical features of the Pistacia vera L. HPG, this microscale architecture provides a favorable microenvironment for the bottom-up remodeling of bone.

Minimization, utilization and disposal of industrial waste are very important from the environmental esthetic point of view. Sludge generated during the treatment of distillery spent wash by electrocoagulation process is highly complex in nature and requires proper disposal. In this context, the present study was conducted to employ the electrocoagulation-generated sludge as a partial replacement of cement while manufacturing the non-constructional building blocks. Various physiochemical and thermo-gravimetric characterization studies have been carried out on electrocoagulation-generated sludge and cement. Mortar specimens with different proportions of sludge ranging from 0 to 15 % by weight of cement were tested for density, compressive strength and leachability of heavy metals by standard method. Results from the analysis showed that the cement-based solidification of EC sludge reduces the heavy metal concentration in the leachate from cement–sludge mortars compared to the EC sludge alone. Reduction in the compressive strength of mortar with 7.5 % substitution of cement by EC sludge was <5 % against the control mortar (without sludge), thereafter the reduction was substantial. The optimum percentage of sludge that can replace the cement with marginal change in the physiochemical properties is found to be 7.5. This can be used in the manufacturing of the non-constructional building material within the industry for their different types of usages such as paving, pot making and fencing of garden without affecting the environment.