you can define CustomScope for request in Spring and use that for defining beans in mule as below.
<spring:bean
class="org.springframework.beans.factory.config.CustomScopeConfigurer">
<spring:property name="scopes">
<spring:map>
<spring:entry key="request">
<spring:bean
class="org.springframework.context.support.SimpleThreadScope" />
</spring:entry>
</spring:map>
</spring:property>
</spring:bean>