Olive Leaf Extract Successfully Incorporated into Biomedical Polymer Filaments

Summary

Researchers from the University of Cádiz have suc­cess­fully incor­po­rated olive leaf extract into PLCL fil­a­ments, a biodegrad­able copoly­mer used in bio­med­ical appli­ca­tions, to cre­ate fil­a­ments with ther­a­peu­tic prop­er­ties for soft-tis­sue engi­neer­ing and drug deliv­ery. The study high­lights the poten­tial of using super­crit­i­cal fluid impreg­na­tion to enhance the bioavail­abil­ity of bioac­tive com­pounds from olive waste, offer­ing a sus­tain­able and effec­tive method for deliv­er­ing antiox­i­dants with poten­tial med­ical appli­ca­tions.

A team of researchers from the Chemical Engineering and Food Technology Department at the University of Cádiz, Spain, has pub­lished research on incor­po­rat­ing olive leaf extract into bio­med­ical poly­mer fil­a­ments.

The fil­a­ments in ques­tion com­prise poly(L‑lactic acid-co-capro­lac­tone) (PLCL), a biodegrad­able, non-toxic copoly­mer used in bio­med­ical appli­ca­tions. 

PLCL typ­i­cally degrades within the human body for up to three years, mak­ing it well-suited for appli­ca­tions that require con­trolled release or even­tual resorp­tion into the body. Such appli­ca­tions include soft-tis­sue engi­neer­ing and sus­tained drug deliv­ery.

The authors cite the grow­ing recog­ni­tion of the need to find new ways to val­orize agri-food waste as part of a move toward a sus­tain­able bio-econ­omy model. 

Olive waste prod­ucts are the focus of a sig­nif­i­cant amount of research in this regard, espe­cially in Spain. 

They are rich in numer­ous bioac­tive com­pounds, such as oleu­ropein, hydrox­y­ty­rosol and phe­no­lic acids, which have demon­strated ther­a­peu­tic prop­er­ties, includ­ing antivi­ral, antimi­cro­bial, anti-inflam­ma­tory and antiox­i­dant activ­i­ties.

These prop­er­ties are also cen­tral to the team’s ratio­nale. Antioxidants, in par­tic­u­lar, are known to have sig­nif­i­cant poten­tial in the treat­ment of dis­eases of global con­cern, includ­ing can­cers, neu­rode­gen­er­a­tive dis­eases, and car­dio­vas­cu­lar dis­eases. 

Their ben­e­fi­cial effects depend mainly on their bioac­ces­si­bil­ity and bioavail­abil­ity, how­ever, and main­tain­ing ther­a­peu­tic con­cen­tra­tions is not always pos­si­ble with con­ven­tional deliv­ery meth­ods, mak­ing PLCL a prime can­di­date.

Following the suc­cess­ful prepa­ra­tion of olive leaf extract, a series of assays and other tests were con­ducted to con­firm its antiox­i­dant capac­ity and anti-inflam­ma­tory activ­ity at suf­fi­ciently high lev­els for poten­tial med­ical appli­ca­tions. 

In addi­tion, key phe­no­lic com­pounds, such as oleu­ropein, hydrox­y­ty­rosol and lute­olin-7-glu­co­side, were detected in suit­able con­cen­tra­tions.

The incor­po­ra­tion of olive leaf extract into PLCL fil­a­ments was then attempted using super­crit­i­cal impreg­na­tion, a tech­nique that has been suc­cess­fully applied to other poly­mers, such as PETG and PLGA. 

The process relies on the prop­er­ties of super­crit­i­cal flu­ids, which are between those of liq­uids and gases.

Supercritical fluid impreg­na­tion offers numer­ous advan­tages over con­ven­tional meth­ods. These include a vir­tual lack of sur­face ten­sion, highly effi­cient deliv­ery, rapid dif­fu­sion into the car­rier matrix, the abil­ity to con­trol drug load­ing and the elim­i­na­tion of organic sol­vent residues. The last of these is par­tic­u­larly rel­e­vant in the con­text of sus­tain­able man­u­fac­tur­ing.

Traditional organic sol­vents, such as those used exten­sively in the phar­ma­ceu­ti­cal indus­try, pose sig­nif­i­cant eco­log­i­cal and health risks due to their volatil­ity, tox­i­c­ity and per­sis­tence in the envi­ron­ment. 

In con­trast, super­crit­i­cal car­bon diox­ide, the sol­vent used in this process, is chem­i­cally inert, non­toxic and non-flam­ma­ble. Carbon diox­ide extrac­tion is also con­sid­ered sus­tain­able due to its closed-loop sys­tems and the abil­ity to cap­ture and reuse car­bon diox­ide, min­i­miz­ing waste and energy con­sump­tion.

By sub­ject­ing the poly­mer to a super­crit­i­cal fluid envi­ron­ment under care­fully con­trolled con­di­tions, olive leaf extract mol­e­cules were suc­cess­fully dri­ven into the poly­mer matrix. 

The researchers adjusted vari­ables such as tem­per­a­ture, pres­sure, co-sol­vent ratio and impreg­na­tion time until the con­di­tions were suf­fi­ciently opti­mized to yield fil­a­ments with uni­formly dis­trib­uted active com­pounds that pre­served the bio­log­i­cal activ­ity of the extract. 

Additionally, analy­sis of the material’s mechan­i­cal prop­er­ties revealed that the impreg­nated fil­a­ments retained suf­fi­cient strength and flex­i­bil­ity for bio­med­ical use.

The authors believe that their find­ings con­firm the suit­abil­ity of PLCL fil­a­ments impreg­nated with olive leaf extract for a range of poten­tial bio­med­ical appli­ca­tions, offer­ing enhanced bio­com­pat­i­bil­ity, reduced inflam­ma­tory responses and improved over­all per­for­mance due to the sus­tained release of nat­ural antiox­i­dants.

They note, how­ever, that sig­nif­i­cant chal­lenges remain and that fur­ther research is needed, par­tic­u­larly in vitro and in vivo stud­ies.

• Oritental Journal of Chemistry
• Molecules