Utilization of Carica papaya latex on coating of SPIONs for dye removal and drug delivery

Latex, a milky substance found in a variety of plants which is a natural source of biologically active compounds. In this study, Latex was collected from raw Carica papaya and was characterized using UV–Vis, FTIR and GC–MS analyses. Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) were synthesized, coated with C. papaya latex (PL-Sp) and characterized using UV–Vis, FT-IR, SEM–EDX, XRD, VSM and Zeta potential analyses. SPIONs and latex coated SPIONs (PL-Sp) were used in batch adsorption study for effective removal of Methylene blue (MB) dye, where (PL-Sp) removed MB dye effectively. Further the PL-Sp was used to produce a nanoconjugate loaded with curcumin and it was characterized using UV–Vis spectrophotometer, FT-IR, SEM–EDX, XRD, VSM and Zeta potential. It showed a sustained drug release pattern and also found to have good antibacterial and anticancer activity.

Biochemical Properties and Anti-Biofilm Activity of Chitosan-Immobilized Papain

Chitosan, the product of chitin deacetylation, is an excellent candidate for enzyme immobilization purposes. Here we demonstrate that papain, an endolytic cysteine protease (EC: 3.4.22.2) from Carica papaya latex immobilized on the matrixes of medium molecular (200 kDa) and high molecular (350 kDa) weight chitosans exhibits anti-biofilm activity and increases the antimicrobials efficiency against biofilm-embedded bacteria. Immobilization in glycine buffer (pH 9.0) allowed adsorption up to 30% of the total protein (mg g chitosan−1) and specific activity (U mg protein−1), leading to the preservation of more than 90% of the initial total activity (U mL−1). While optimal pH and temperature of the immobilized papain did not change, the immobilized enzyme exhibited elevated thermal stability and 6–7-fold longer half-life time in comparison with the soluble papain. While one-half of the total enzyme dissociates from both carriers in 24 h, this property could be used for wound-dressing materials design with dosed release of the enzyme to overcome the relatively high cytotoxicity of soluble papain. Our results indicate that both soluble and immobilized papain efficiently destroy biofilms formed by Staphylococcus aureus and Staphylococcus epidermidis. As a consequence, papain, both soluble and immobilized on medium molecular weight chitosan, is capable of potentiating the efficacy of antimicrobials against biofilm-embedded Staphylococci. Thus, papain immobilized on medium molecular weight chitosan appears a presumably beneficial agent for outer wound treatment for biofilms destruction, increasing antimicrobial treatment effectiveness.

One-step purification and freeze stability of papain at acidic pH values

Papain is a proteolytic enzyme of great commercial value. It is a cysteine protease highly expressed in Carica papaya fruit latex, but also present in papaya leaves. Purification procedures mostly deal with the latex and include a combination of precipitation and/or chromatographic techniques. Due to its solubility, structure and activity characteristics, the pH and salt content play significant roles in handling papain extracts. Here we report a simple, rapid and easily scalable procedure for papain purification from papaya leaves, which contain different contaminants as compared to papaya latex. Sodium chloride precipitation of contaminants at pH 5 followed by ammonium sulphate precipitation resulted in the removal of other leaf proteins and protein fragments from papain solution and about a 3-fold purification. The procedure also benefits from the suppression of autoproteolysis and preservation of the native structure, as confirmed by FTIR analysis, and the high recovery of activity of over 80%.

Optimization of Crude Papaya (Carica papaya) Protease in Soft-Unripened Cheese Preparation

The use of plant protease instead of chymosin for producing cheese has become a trend which is aimed at lacto-vegetarian consumers and religion based ecological markets. In this context, the present investigation was carried out in order to utilize milk clotting enzyme from Papaya (Carica papaya). Numerical optimization study revealed that maximum milk clotting activity was achieved at pH 6.5, temperature 70℃ and enzyme concentration 1 g/1000 ml milk using papaya protease as coagulant. Protein, ash and calcium showed no significant (p>0.05) difference among the cheeses made using different coagulants. However, significantly (p<0.05) higher levels of moisture and ash, and lower levels of fat were observed in the cheese produced by papaya protease compared to that made using rennet. Papaya protease significantly enhanced the spreadability of cheese while the other sensory properties were similar to the control except aftertaste. The results revealed that the papaya latex as crude papaya protease may have potential application for the manufacture of soft-unripened cheese and further could be utilized as a milk coagulant in cheese making.

Physico-Chemical Treatment of a Wastewater Collector Loaded with Metals and Suspension Material by The Solution of Raw Carica papaya Latex

The papaya (Carica papaya), of the family Caricaceae, is a tree-like tropical plant, native to Central and South America. Papaya cultivation extends to all warm and humid countries. The present study consists in using the solution of raw Carica papaya latex (SLCP) cultivated in Benin as a natural biodegradable flocculant in a physico-chemical process to treat liquid discharges loaded with metals including iron, copper, zinc, and manganese; and suspended matter, and also to test its efficiency against other products commonly used in wastewater treatment. The tests were carried out on water samples from the wastewater collector that runs through the Agla district in Cotonou. The comparative study with a commonly used flocculant, aluminium sulphate, showed outstanding competitiveness with a high flocculation power for the solution of Carica papaya raw latex. In six water samples from the collector with average concentrations of iron, copper, zinc and manganese of 18.20 mg/L ; 2.50mg/L ; 3.80 mg/L and 3.70 mg/L respectively, the percentages of metal removal exceeded 90% for iron and manganese and around 85% for copper and zinc with the combination FeCl3 + SLCP. The NaOH + SLCP combination showed a very significant effect on the removal of metals (96% reduction) and suspended matter.